1 /*
2 * Copyright (c) 2018, 2025, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "cds/aotArtifactFinder.hpp"
26 #include "cds/aotClassInitializer.hpp"
27 #include "cds/aotClassLocation.hpp"
28 #include "cds/archiveBuilder.hpp"
29 #include "cds/archiveHeapLoader.hpp"
30 #include "cds/archiveHeapWriter.hpp"
31 #include "cds/archiveUtils.hpp"
32 #include "cds/cdsAccess.hpp"
33 #include "cds/cdsConfig.hpp"
34 #include "cds/cdsEnumKlass.hpp"
35 #include "cds/cdsHeapVerifier.hpp"
36 #include "cds/heapShared.hpp"
37 #include "cds/metaspaceShared.hpp"
38 #include "classfile/classLoaderData.hpp"
39 #include "classfile/classLoaderExt.hpp"
40 #include "classfile/javaClasses.inline.hpp"
41 #include "classfile/modules.hpp"
42 #include "classfile/stringTable.hpp"
43 #include "classfile/symbolTable.hpp"
44 #include "classfile/systemDictionary.hpp"
45 #include "classfile/systemDictionaryShared.hpp"
46 #include "classfile/vmClasses.hpp"
47 #include "classfile/vmSymbols.hpp"
48 #include "gc/shared/collectedHeap.hpp"
49 #include "gc/shared/gcLocker.hpp"
50 #include "gc/shared/gcVMOperations.hpp"
51 #include "logging/log.hpp"
52 #include "logging/logStream.hpp"
53 #include "memory/iterator.inline.hpp"
54 #include "memory/resourceArea.hpp"
55 #include "memory/universe.hpp"
56 #include "oops/compressedOops.inline.hpp"
57 #include "oops/fieldStreams.inline.hpp"
58 #include "oops/objArrayOop.inline.hpp"
59 #include "oops/oop.inline.hpp"
60 #include "oops/typeArrayOop.inline.hpp"
61 #include "prims/jvmtiExport.hpp"
62 #include "runtime/arguments.hpp"
63 #include "runtime/fieldDescriptor.inline.hpp"
64 #include "runtime/init.hpp"
65 #include "runtime/javaCalls.hpp"
66 #include "runtime/mutexLocker.hpp"
67 #include "runtime/safepointVerifiers.hpp"
68 #include "utilities/bitMap.inline.hpp"
69 #include "utilities/copy.hpp"
70 #if INCLUDE_G1GC
71 #include "gc/g1/g1CollectedHeap.hpp"
72 #endif
73
74 #if INCLUDE_CDS_JAVA_HEAP
75
76 struct ArchivableStaticFieldInfo {
77 const char* klass_name;
78 const char* field_name;
79 InstanceKlass* klass;
80 int offset;
81 BasicType type;
82
83 ArchivableStaticFieldInfo(const char* k, const char* f)
84 : klass_name(k), field_name(f), klass(nullptr), offset(0), type(T_ILLEGAL) {}
85
86 bool valid() {
87 return klass_name != nullptr;
88 }
89 };
90
91 class HeapShared::ContextMark : public StackObj {
92 ResourceMark rm;
93 public:
94 ContextMark(const char* c) : rm{} {
95 _context->push(c);
96 }
97 ~ContextMark() {
98 _context->pop();
99 }
100 };
101
102 DumpedInternedStrings *HeapShared::_dumped_interned_strings = nullptr;
103
104 size_t HeapShared::_alloc_count[HeapShared::ALLOC_STAT_SLOTS];
105 size_t HeapShared::_alloc_size[HeapShared::ALLOC_STAT_SLOTS];
106 size_t HeapShared::_total_obj_count;
107 size_t HeapShared::_total_obj_size;
108
109 #ifndef PRODUCT
110 #define ARCHIVE_TEST_FIELD_NAME "archivedObjects"
111 static Array<char>* _archived_ArchiveHeapTestClass = nullptr;
112 static const char* _test_class_name = nullptr;
113 static Klass* _test_class = nullptr;
114 static const ArchivedKlassSubGraphInfoRecord* _test_class_record = nullptr;
115 #endif
116
117
118 //
119 // If you add new entries to the following tables, you should know what you're doing!
120 //
121
122 static ArchivableStaticFieldInfo archive_subgraph_entry_fields[] = {
123 {"java/lang/Integer$IntegerCache", "archivedCache"},
124 {"java/lang/Long$LongCache", "archivedCache"},
125 {"java/lang/Byte$ByteCache", "archivedCache"},
126 {"java/lang/Short$ShortCache", "archivedCache"},
127 {"java/lang/Character$CharacterCache", "archivedCache"},
128 {"java/util/jar/Attributes$Name", "KNOWN_NAMES"},
129 {"sun/util/locale/BaseLocale", "constantBaseLocales"},
130 {"jdk/internal/module/ArchivedModuleGraph", "archivedModuleGraph"},
131 {"java/util/ImmutableCollections", "archivedObjects"},
132 {"java/lang/ModuleLayer", "EMPTY_LAYER"},
133 {"java/lang/module/Configuration", "EMPTY_CONFIGURATION"},
134 {"jdk/internal/math/FDBigInteger", "archivedCaches"},
135 {"java/lang/reflect/Proxy$ProxyBuilder", "archivedData"}, // FIXME -- requires AOTClassLinking
136
137 #ifndef PRODUCT
138 {nullptr, nullptr}, // Extra slot for -XX:ArchiveHeapTestClass
139 #endif
140 {nullptr, nullptr},
141 };
142
143 // full module graph
144 static ArchivableStaticFieldInfo fmg_archive_subgraph_entry_fields[] = {
145 {"jdk/internal/loader/ArchivedClassLoaders", "archivedClassLoaders"},
146 {ARCHIVED_BOOT_LAYER_CLASS, ARCHIVED_BOOT_LAYER_FIELD},
147 {"java/lang/Module$ArchivedData", "archivedData"},
148 {nullptr, nullptr},
149 };
150
151 KlassSubGraphInfo* HeapShared::_dump_time_special_subgraph;
152 ArchivedKlassSubGraphInfoRecord* HeapShared::_run_time_special_subgraph;
153 GrowableArrayCHeap<OopHandle, mtClassShared>* HeapShared::_pending_roots = nullptr;
154 GrowableArrayCHeap<const char*, mtClassShared>* HeapShared::_context = nullptr;
155 GrowableArrayCHeap<OopHandle, mtClassShared>* HeapShared::_root_segments = nullptr;
156 int HeapShared::_root_segment_max_size_elems;
157 OopHandle HeapShared::_scratch_basic_type_mirrors[T_VOID+1];
158 MetaspaceObjToOopHandleTable* HeapShared::_scratch_objects_table = nullptr;
159
160 static bool is_subgraph_root_class_of(ArchivableStaticFieldInfo fields[], InstanceKlass* ik) {
161 for (int i = 0; fields[i].valid(); i++) {
162 if (fields[i].klass == ik) {
163 return true;
164 }
165 }
166 return false;
167 }
168
169 bool HeapShared::is_subgraph_root_class(InstanceKlass* ik) {
170 return is_subgraph_root_class_of(archive_subgraph_entry_fields, ik) ||
171 is_subgraph_root_class_of(fmg_archive_subgraph_entry_fields, ik);
172 }
173
174 unsigned HeapShared::oop_hash(oop const& p) {
175 // Do not call p->identity_hash() as that will update the
176 // object header.
177 return primitive_hash(cast_from_oop<intptr_t>(p));
178 }
179
180 static void reset_states(oop obj, TRAPS) {
181 Handle h_obj(THREAD, obj);
182 InstanceKlass* klass = InstanceKlass::cast(obj->klass());
183 TempNewSymbol method_name = SymbolTable::new_symbol("resetArchivedStates");
184 Symbol* method_sig = vmSymbols::void_method_signature();
185
186 while (klass != nullptr) {
187 Method* method = klass->find_method(method_name, method_sig);
188 if (method != nullptr) {
189 assert(method->is_private(), "must be");
190 if (log_is_enabled(Debug, cds)) {
191 ResourceMark rm(THREAD);
192 log_debug(cds)(" calling %s", method->name_and_sig_as_C_string());
193 }
194 JavaValue result(T_VOID);
195 JavaCalls::call_special(&result, h_obj, klass,
196 method_name, method_sig, CHECK);
197 }
198 klass = klass->java_super();
199 }
200 }
201
202 void HeapShared::reset_archived_object_states(TRAPS) {
203 assert(CDSConfig::is_dumping_heap(), "dump-time only");
204 log_debug(cds)("Resetting platform loader");
205 reset_states(SystemDictionary::java_platform_loader(), CHECK);
206 log_debug(cds)("Resetting system loader");
207 reset_states(SystemDictionary::java_system_loader(), CHECK);
208
209 // Clean up jdk.internal.loader.ClassLoaders::bootLoader(), which is not
210 // directly used for class loading, but rather is used by the core library
211 // to keep track of resources, etc, loaded by the null class loader.
212 //
213 // Note, this object is non-null, and is not the same as
214 // ClassLoaderData::the_null_class_loader_data()->class_loader(),
215 // which is null.
216 log_debug(cds)("Resetting boot loader");
217 JavaValue result(T_OBJECT);
218 JavaCalls::call_static(&result,
219 vmClasses::jdk_internal_loader_ClassLoaders_klass(),
220 vmSymbols::bootLoader_name(),
221 vmSymbols::void_BuiltinClassLoader_signature(),
222 CHECK);
223 Handle boot_loader(THREAD, result.get_oop());
224 reset_states(boot_loader(), CHECK);
225 }
226
227 HeapShared::ArchivedObjectCache* HeapShared::_archived_object_cache = nullptr;
228
229 bool HeapShared::has_been_archived(oop obj) {
230 assert(CDSConfig::is_dumping_heap(), "dump-time only");
231 return archived_object_cache()->get(obj) != nullptr;
232 }
233
234 int HeapShared::append_root(oop obj) {
235 assert(CDSConfig::is_dumping_heap(), "dump-time only");
236 if (obj != nullptr) {
237 assert(has_been_archived(obj), "must be");
238 }
239 // No GC should happen since we aren't scanning _pending_roots.
240 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
241
242 OopHandle oh(Universe::vm_global(), obj);
243 return _pending_roots->append(oh);
244 }
245
246 objArrayOop HeapShared::root_segment(int segment_idx) {
247 if (CDSConfig::is_dumping_heap() && !CDSConfig::is_dumping_final_static_archive()) {
248 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
249 } else {
250 assert(CDSConfig::is_using_archive(), "must be");
251 }
252
253 objArrayOop segment = (objArrayOop)_root_segments->at(segment_idx).resolve();
254 assert(segment != nullptr, "should have been initialized");
255 return segment;
256 }
257
258 inline unsigned int oop_handle_hash(const OopHandle& oh) {
259 oop o = oh.resolve();
260 if (o == nullptr) {
261 return 0;
262 } else {
263 return o->identity_hash();
264 }
265 }
266
267 inline bool oop_handle_equals(const OopHandle& a, const OopHandle& b) {
268 return a.resolve() == b.resolve();
269 }
270
271 class OrigToScratchObjectTable: public ResourceHashtable<OopHandle, OopHandle,
272 36137, // prime number
273 AnyObj::C_HEAP,
274 mtClassShared,
275 oop_handle_hash,
276 oop_handle_equals> {};
277
278 static OrigToScratchObjectTable* _orig_to_scratch_object_table = nullptr;
279
280 void HeapShared::track_scratch_object(oop orig_obj, oop scratch_obj) {
281 MutexLocker ml(ArchivedObjectTables_lock, Mutex::_no_safepoint_check_flag);
282 if (_orig_to_scratch_object_table == nullptr) {
283 _orig_to_scratch_object_table = new (mtClass)OrigToScratchObjectTable();
284 }
285
286 OopHandle orig_h(Universe::vm_global(), orig_obj);
287 OopHandle scratch_h(Universe::vm_global(), scratch_obj);
288 _orig_to_scratch_object_table->put_when_absent(orig_h, scratch_h);
289 }
290
291 oop HeapShared::orig_to_scratch_object(oop orig_obj) {
292 MutexLocker ml(ArchivedObjectTables_lock, Mutex::_no_safepoint_check_flag);
293 if (_orig_to_scratch_object_table != nullptr) {
294 OopHandle orig(&orig_obj);
295 OopHandle* v = _orig_to_scratch_object_table->get(orig);
296 if (v != nullptr) {
297 return v->resolve();
298 }
299 }
300 return nullptr;
301 }
302
303 // Permanent oops are used to support AOT-compiled methods, which may have in-line references
304 // to Strings and MH oops.
305 //
306 // At runtime, these oops are stored in _runtime_permanent_oops (which keeps them alive forever)
307 // and are accssed vis CDSAccess::get_archived_object(int).
308 struct PermanentOopInfo {
309 int _index; // Gets assigned only if HeapShared::get_archived_object_permanent_index() has been called on the object
310 int _heap_offset; // Offset of the object from the bottom of the archived heap.
311 PermanentOopInfo(int index, int heap_offset) : _index(index), _heap_offset(heap_offset) {}
312 };
313
314 class PermanentOopTable: public ResourceHashtable<OopHandle, PermanentOopInfo,
315 36137, // prime number
316 AnyObj::C_HEAP,
317 mtClassShared,
318 oop_handle_hash,
319 oop_handle_equals> {};
320
321 static int _dumptime_permanent_oop_count = 0;
322 static PermanentOopTable* _dumptime_permanent_oop_table = nullptr;
323 static GrowableArrayCHeap<OopHandle, mtClassShared>* _runtime_permanent_oops = nullptr;
324
325 // ArchiveHeapWriter adds each archived heap object to _dumptime_permanent_oop_table,
326 // so we can remember their offset (from the bottom of the archived heap).
327 void HeapShared::add_to_permanent_oop_table(oop obj, int offset) {
328 assert_at_safepoint();
329 if (_dumptime_permanent_oop_table == nullptr) {
330 _dumptime_permanent_oop_table = new (mtClass)PermanentOopTable();
331 }
332
333 PermanentOopInfo info(-1, offset);
334 OopHandle oh(Universe::vm_global(), obj);
335 _dumptime_permanent_oop_table->put_when_absent(oh, info);
336 }
337
338 // A permanent index is assigned to an archived object ONLY when
339 // the AOT compiler calls this function.
340 int HeapShared::get_archived_object_permanent_index(oop obj) {
341 MutexLocker ml(ArchivedObjectTables_lock, Mutex::_no_safepoint_check_flag);
342
343 if (!CDSConfig::is_dumping_heap()) {
344 return -1; // Called by the Leyden old workflow
345 }
346 if (_dumptime_permanent_oop_table == nullptr) {
347 return -1;
348 }
349
350 if (_orig_to_scratch_object_table != nullptr) {
351 OopHandle orig(&obj);
352 OopHandle* v = _orig_to_scratch_object_table->get(orig);
353 if (v != nullptr) {
354 obj = v->resolve();
355 }
356 }
357
358 OopHandle tmp(&obj);
359 PermanentOopInfo* info = _dumptime_permanent_oop_table->get(tmp);
360 if (info == nullptr) {
361 return -1;
362 } else {
363 if (info->_index < 0) {
364 info->_index = _dumptime_permanent_oop_count++;
365 }
366 return info->_index;
367 }
368 }
369
370 oop HeapShared::get_archived_object(int permanent_index) {
371 assert(permanent_index >= 0, "sanity");
372 assert(ArchiveHeapLoader::is_in_use(), "sanity");
373 assert(_runtime_permanent_oops != nullptr, "sanity");
374
375 return _runtime_permanent_oops->at(permanent_index).resolve();
376 }
377
378 // Remember all archived heap objects that have a permanent index.
379 // table[i] = offset of oop whose permanent index is i.
380 void CachedCodeDirectoryInternal::dumptime_init_internal() {
381 const int count = _dumptime_permanent_oop_count;
382 if (count == 0) {
383 // Avoid confusing CDS code with zero-sized tables, just return.
384 log_info(cds)("No permanent oops");
385 _permanent_oop_count = count;
386 _permanent_oop_offsets = nullptr;
387 return;
388 }
389
390 int* table = (int*)CDSAccess::allocate_from_code_cache(count * sizeof(int));
391 for (int i = 0; i < count; i++) {
392 table[count] = -1;
393 }
394 _dumptime_permanent_oop_table->iterate([&](OopHandle o, PermanentOopInfo& info) {
395 int index = info._index;
396 if (index >= 0) {
397 assert(index < count, "sanity");
398 table[index] = info._heap_offset;
399 }
400 return true; // continue
401 });
402
403 for (int i = 0; i < count; i++) {
404 assert(table[i] >= 0, "must be");
405 }
406
407 log_info(cds)("Dumped %d permanent oops", count);
408
409 _permanent_oop_count = count;
410 CDSAccess::set_pointer(&_permanent_oop_offsets, table);
411 }
412
413 // This is called during the bootstrap of the production run, before any GC can happen.
414 // Record each permanent oop in a OopHandle for GC safety.
415 void CachedCodeDirectoryInternal::runtime_init_internal() {
416 int count = _permanent_oop_count;
417 int* table = _permanent_oop_offsets;
418 _runtime_permanent_oops = new GrowableArrayCHeap<OopHandle, mtClassShared>();
419 for (int i = 0; i < count; i++) {
420 oop obj = ArchiveHeapLoader::oop_from_offset(table[i]);
421 OopHandle oh(Universe::vm_global(), obj);
422 _runtime_permanent_oops->append(oh);
423 }
424 };
425
426 void HeapShared::get_segment_indexes(int idx, int& seg_idx, int& int_idx) {
427 assert(_root_segment_max_size_elems > 0, "sanity");
428
429 // Try to avoid divisions for the common case.
430 if (idx < _root_segment_max_size_elems) {
431 seg_idx = 0;
432 int_idx = idx;
433 } else {
434 seg_idx = idx / _root_segment_max_size_elems;
435 int_idx = idx % _root_segment_max_size_elems;
436 }
437
438 assert(idx == seg_idx * _root_segment_max_size_elems + int_idx,
439 "sanity: %d index maps to %d segment and %d internal", idx, seg_idx, int_idx);
440 }
441
442 // Returns an objArray that contains all the roots of the archived objects
443 oop HeapShared::get_root(int index, bool clear) {
444 assert(index >= 0, "sanity");
445 assert(!CDSConfig::is_dumping_heap() && CDSConfig::is_using_archive(), "runtime only");
446 assert(!_root_segments->is_empty(), "must have loaded shared heap");
447 int seg_idx, int_idx;
448 get_segment_indexes(index, seg_idx, int_idx);
449 oop result = root_segment(seg_idx)->obj_at(int_idx);
450 if (clear) {
451 clear_root(index);
452 }
453 return result;
454 }
455
456 void HeapShared::clear_root(int index) {
457 assert(index >= 0, "sanity");
458 assert(CDSConfig::is_using_archive(), "must be");
459 if (ArchiveHeapLoader::is_in_use()) {
460 int seg_idx, int_idx;
461 get_segment_indexes(index, seg_idx, int_idx);
462 if (log_is_enabled(Debug, cds, heap)) {
463 oop old = root_segment(seg_idx)->obj_at(int_idx);
464 log_debug(cds, heap)("Clearing root %d: was " PTR_FORMAT, index, p2i(old));
465 }
466 root_segment(seg_idx)->obj_at_put(int_idx, nullptr);
467 }
468 }
469
470 bool HeapShared::archive_object(oop obj, oop referrer, KlassSubGraphInfo* subgraph_info) {
471 assert(CDSConfig::is_dumping_heap(), "dump-time only");
472
473 assert(!obj->is_stackChunk(), "do not archive stack chunks");
474 if (has_been_archived(obj)) {
475 return true;
476 }
477
478 if (ArchiveHeapWriter::is_too_large_to_archive(obj->size())) {
479 log_debug(cds, heap)("Cannot archive, object (" PTR_FORMAT ") is too large: %zu",
480 p2i(obj), obj->size());
481 debug_trace();
482 return false;
483 } else {
484 count_allocation(obj->size());
485 ArchiveHeapWriter::add_source_obj(obj);
486 CachedOopInfo info = make_cached_oop_info(obj, referrer);
487 archived_object_cache()->put_when_absent(obj, info);
488 archived_object_cache()->maybe_grow();
489 mark_native_pointers(obj);
490
491 Klass* k = obj->klass();
492 if (k->is_instance_klass()) {
493 // Whenever we see a non-array Java object of type X, we mark X to be aot-initialized.
494 // This ensures that during the production run, whenever Java code sees a cached object
495 // of type X, we know that X is already initialized. (see TODO comment below ...)
496
497 if (InstanceKlass::cast(k)->is_enum_subclass()
498 // We can't rerun <clinit> of enum classes (see cdsEnumKlass.cpp) so
499 // we must store them as AOT-initialized.
500 || (subgraph_info == _dump_time_special_subgraph))
501 // TODO: we do this only for the special subgraph for now. Extending this to
502 // other subgraphs would require more refactoring of the core library (such as
503 // move some initialization logic into runtimeSetup()).
504 //
505 // For the other subgraphs, we have a weaker mechanism to ensure that
506 // all classes in a subgraph are initialized before the subgraph is programmatically
507 // returned from jdk.internal.misc.CDS::initializeFromArchive().
508 // See HeapShared::initialize_from_archived_subgraph().
509 {
510 AOTArtifactFinder::add_aot_inited_class(InstanceKlass::cast(k));
511 }
512
513 if (java_lang_Class::is_instance(obj)) {
514 Klass* mirror_k = java_lang_Class::as_Klass(obj);
515 if (mirror_k != nullptr) {
516 AOTArtifactFinder::add_cached_class(mirror_k);
517 }
518 } else if (java_lang_invoke_ResolvedMethodName::is_instance(obj)) {
519 Method* m = java_lang_invoke_ResolvedMethodName::vmtarget(obj);
520 if (m != nullptr) {
521 InstanceKlass* method_holder = m->method_holder();
522 AOTArtifactFinder::add_cached_class(method_holder);
523 }
524 }
525 }
526
527 if (log_is_enabled(Debug, cds, heap)) {
528 ResourceMark rm;
529 LogTarget(Debug, cds, heap) log;
530 LogStream out(log);
531 out.print("Archived heap object " PTR_FORMAT " : %s ",
532 p2i(obj), obj->klass()->external_name());
533 if (java_lang_Class::is_instance(obj)) {
534 Klass* k = java_lang_Class::as_Klass(obj);
535 if (k != nullptr) {
536 out.print("%s", k->external_name());
537 } else {
538 out.print("primitive");
539 }
540 }
541 out.cr();
542 }
543
544 return true;
545 }
546 }
547
548 class MetaspaceObjToOopHandleTable: public ResourceHashtable<MetaspaceObj*, OopHandle,
549 36137, // prime number
550 AnyObj::C_HEAP,
551 mtClassShared> {
552 public:
553 oop get_oop(MetaspaceObj* ptr) {
554 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
555 OopHandle* handle = get(ptr);
556 if (handle != nullptr) {
557 return handle->resolve();
558 } else {
559 return nullptr;
560 }
561 }
562 void set_oop(MetaspaceObj* ptr, oop o) {
563 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
564 OopHandle handle(Universe::vm_global(), o);
565 bool is_new = put(ptr, handle);
566 assert(is_new, "cannot set twice");
567 }
568 void remove_oop(MetaspaceObj* ptr) {
569 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
570 OopHandle* handle = get(ptr);
571 if (handle != nullptr) {
572 handle->release(Universe::vm_global());
573 remove(ptr);
574 }
575 }
576 };
577
578 void HeapShared::add_scratch_resolved_references(ConstantPool* src, objArrayOop dest) {
579 if (SystemDictionaryShared::is_builtin_loader(src->pool_holder()->class_loader_data())) {
580 _scratch_objects_table->set_oop(src, dest);
581 }
582 }
583
584 objArrayOop HeapShared::scratch_resolved_references(ConstantPool* src) {
585 return (objArrayOop)_scratch_objects_table->get_oop(src);
586 }
587
588 void HeapShared::init_dumping() {
589 _scratch_objects_table = new (mtClass)MetaspaceObjToOopHandleTable();
590 _pending_roots = new GrowableArrayCHeap<OopHandle, mtClassShared>(500);
591 }
592
593 void HeapShared::init_scratch_objects_for_basic_type_mirrors(TRAPS) {
594 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
595 BasicType bt = (BasicType)i;
596 if (!is_reference_type(bt)) {
597 oop m = java_lang_Class::create_basic_type_mirror(type2name(bt), bt, CHECK);
598 _scratch_basic_type_mirrors[i] = OopHandle(Universe::vm_global(), m);
599 track_scratch_object(Universe::java_mirror(bt), m);
600 }
601 }
602 }
603
604 // Given java_mirror that represents a (primitive or reference) type T,
605 // return the "scratch" version that represents the same type T.
606 // Note that if java_mirror will be returned if it's already a
607 // scratch mirror.
608 //
609 // See java_lang_Class::create_scratch_mirror() for more info.
610 oop HeapShared::scratch_java_mirror(oop java_mirror) {
611 assert(java_lang_Class::is_instance(java_mirror), "must be");
612
613 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
614 BasicType bt = (BasicType)i;
615 if (!is_reference_type(bt)) {
616 if (_scratch_basic_type_mirrors[i].resolve() == java_mirror) {
617 return java_mirror;
618 }
619 }
620 }
621
622 if (java_lang_Class::is_primitive(java_mirror)) {
623 return scratch_java_mirror(java_lang_Class::as_BasicType(java_mirror));
624 } else {
625 return scratch_java_mirror(java_lang_Class::as_Klass(java_mirror));
626 }
627 }
628
629 oop HeapShared::scratch_java_mirror(BasicType t) {
630 assert((uint)t < T_VOID+1, "range check");
631 assert(!is_reference_type(t), "sanity");
632 return _scratch_basic_type_mirrors[t].resolve();
633 }
634
635 oop HeapShared::scratch_java_mirror(Klass* k) {
636 return _scratch_objects_table->get_oop(k);
637 }
638
639 void HeapShared::set_scratch_java_mirror(Klass* k, oop mirror) {
640 track_scratch_object(k->java_mirror(), mirror);
641 _scratch_objects_table->set_oop(k, mirror);
642 }
643
644 void HeapShared::remove_scratch_objects(Klass* k) {
645 // Klass is being deallocated. Java mirror can still be alive, and it should not
646 // point to dead klass. We need to break the link from mirror to the Klass.
647 // See how InstanceKlass::deallocate_contents does it for normal mirrors.
648 oop mirror = _scratch_objects_table->get_oop(k);
649 if (mirror != nullptr) {
650 java_lang_Class::set_klass(mirror, nullptr);
651 }
652 _scratch_objects_table->remove_oop(k);
653 if (k->is_instance_klass()) {
654 _scratch_objects_table->remove(InstanceKlass::cast(k)->constants());
655 }
656 if (mirror != nullptr) {
657 OopHandle tmp(&mirror);
658 OopHandle* v = _orig_to_scratch_object_table->get(tmp);
659 if (v != nullptr) {
660 oop scratch_mirror = v->resolve();
661 java_lang_Class::set_klass(scratch_mirror, nullptr);
662 _orig_to_scratch_object_table->remove(tmp);
663 }
664 }
665 }
666
667 //TODO: we eventually want a more direct test for these kinds of things.
668 //For example the JVM could record some bit of context from the creation
669 //of the klass, such as who called the hidden class factory. Using
670 //string compares on names is fragile and will break as soon as somebody
671 //changes the names in the JDK code. See discussion in JDK-8342481 for
672 //related ideas about marking AOT-related classes.
673 bool HeapShared::is_lambda_form_klass(InstanceKlass* ik) {
674 return ik->is_hidden() &&
675 (ik->name()->starts_with("java/lang/invoke/LambdaForm$MH+") ||
676 ik->name()->starts_with("java/lang/invoke/LambdaForm$DMH+") ||
677 ik->name()->starts_with("java/lang/invoke/LambdaForm$BMH+") ||
678 ik->name()->starts_with("java/lang/invoke/LambdaForm$VH+"));
679 }
680
681 bool HeapShared::is_lambda_proxy_klass(InstanceKlass* ik) {
682 return ik->is_hidden() && (ik->name()->index_of_at(0, "$$Lambda+", 9) > 0);
683 }
684
685 bool HeapShared::is_string_concat_klass(InstanceKlass* ik) {
686 return ik->is_hidden() && ik->name()->starts_with("java/lang/String$$StringConcat");
687 }
688
689 bool HeapShared::is_archivable_hidden_klass(InstanceKlass* ik) {
690 return CDSConfig::is_dumping_method_handles() &&
691 (is_lambda_form_klass(ik) || is_lambda_proxy_klass(ik) || is_string_concat_klass(ik));
692 }
693
694
695 void HeapShared::copy_and_rescan_aot_inited_mirror(InstanceKlass* ik) {
696 ik->set_has_aot_initialized_mirror();
697 if (AOTClassInitializer::is_runtime_setup_required(ik)) {
698 ik->set_is_runtime_setup_required();
699 }
700
701 oop orig_mirror = ik->java_mirror();
702 oop m = scratch_java_mirror(ik);
703 assert(ik->is_initialized(), "must be");
704
705 int nfields = 0;
706 for (JavaFieldStream fs(ik); !fs.done(); fs.next()) {
707 if (fs.access_flags().is_static()) {
708 fieldDescriptor& fd = fs.field_descriptor();
709 int offset = fd.offset();
710 switch (fd.field_type()) {
711 case T_OBJECT:
712 case T_ARRAY:
713 {
714 oop field_obj = orig_mirror->obj_field(offset);
715 if (offset == java_lang_Class::reflection_data_offset()) {
716 // Class::reflectData use SoftReference, which cannot be archived. Set it
717 // to null and it will be recreated at runtime.
718 field_obj = nullptr;
719 }
720 m->obj_field_put(offset, field_obj);
721 if (field_obj != nullptr) {
722 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, field_obj);
723 assert(success, "sanity");
724 }
725 }
726 break;
727 case T_BOOLEAN:
728 m->bool_field_put(offset, orig_mirror->bool_field(offset));
729 break;
730 case T_BYTE:
731 m->byte_field_put(offset, orig_mirror->byte_field(offset));
732 break;
733 case T_SHORT:
734 m->short_field_put(offset, orig_mirror->short_field(offset));
735 break;
736 case T_CHAR:
737 m->char_field_put(offset, orig_mirror->char_field(offset));
738 break;
739 case T_INT:
740 m->int_field_put(offset, orig_mirror->int_field(offset));
741 break;
742 case T_LONG:
743 m->long_field_put(offset, orig_mirror->long_field(offset));
744 break;
745 case T_FLOAT:
746 m->float_field_put(offset, orig_mirror->float_field(offset));
747 break;
748 case T_DOUBLE:
749 m->double_field_put(offset, orig_mirror->double_field(offset));
750 break;
751 default:
752 ShouldNotReachHere();
753 }
754 nfields ++;
755 }
756 }
757
758 oop class_data = java_lang_Class::class_data(orig_mirror);
759 java_lang_Class::set_class_data(m, class_data);
760 if (class_data != nullptr) {
761 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, class_data);
762 assert(success, "sanity");
763 }
764
765 if (log_is_enabled(Debug, cds, init)) {
766 ResourceMark rm;
767 log_debug(cds, init)("copied %3d field(s) in aot-initialized mirror %s%s%s", nfields, ik->external_name(),
768 ik->is_hidden() ? " (hidden)" : "",
769 ik->is_enum_subclass() ? " (enum)" : "");
770 }
771 }
772
773 static void copy_java_mirror_hashcode(oop orig_mirror, oop scratch_m) {
774 // We need to retain the identity_hash, because it may have been used by some hashtables
775 // in the shared heap.
776 if (!orig_mirror->fast_no_hash_check()) {
777 intptr_t src_hash = orig_mirror->identity_hash();
778 if (UseCompactObjectHeaders) {
779 narrowKlass nk = CompressedKlassPointers::encode(orig_mirror->klass());
780 scratch_m->set_mark(markWord::prototype().set_narrow_klass(nk).copy_set_hash(src_hash));
781 } else {
782 scratch_m->set_mark(markWord::prototype().copy_set_hash(src_hash));
783 }
784 assert(scratch_m->mark().is_unlocked(), "sanity");
785
786 DEBUG_ONLY(intptr_t archived_hash = scratch_m->identity_hash());
787 assert(src_hash == archived_hash, "Different hash codes: original " INTPTR_FORMAT ", archived " INTPTR_FORMAT, src_hash, archived_hash);
788 }
789 }
790
791 static objArrayOop get_archived_resolved_references(InstanceKlass* src_ik) {
792 if (SystemDictionaryShared::is_builtin_loader(src_ik->class_loader_data())) {
793 objArrayOop rr = src_ik->constants()->resolved_references_or_null();
794 if (rr != nullptr && !ArchiveHeapWriter::is_too_large_to_archive(rr)) {
795 return HeapShared::scratch_resolved_references(src_ik->constants());
796 }
797 }
798 return nullptr;
799 }
800
801 void HeapShared::archive_strings() {
802 oop shared_strings_array = StringTable::init_shared_strings_array(_dumped_interned_strings);
803 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, shared_strings_array);
804 // We must succeed because:
805 // - _dumped_interned_strings do not contain any large strings.
806 // - StringTable::init_shared_table() doesn't create any large arrays.
807 assert(success, "shared strings array must not point to arrays or strings that are too large to archive");
808 StringTable::set_shared_strings_array_index(append_root(shared_strings_array));
809 }
810
811 int HeapShared::archive_exception_instance(oop exception) {
812 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, exception);
813 assert(success, "sanity");
814 return append_root(exception);
815 }
816
817 void HeapShared::mark_native_pointers(oop orig_obj) {
818 if (java_lang_Class::is_instance(orig_obj)) {
819 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_Class::klass_offset());
820 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_Class::array_klass_offset());
821 } else if (java_lang_invoke_ResolvedMethodName::is_instance(orig_obj)) {
822 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_invoke_ResolvedMethodName::vmtarget_offset());
823 }
824 }
825
826 void HeapShared::get_pointer_info(oop src_obj, bool& has_oop_pointers, bool& has_native_pointers) {
827 CachedOopInfo* info = archived_object_cache()->get(src_obj);
828 assert(info != nullptr, "must be");
829 has_oop_pointers = info->has_oop_pointers();
830 has_native_pointers = info->has_native_pointers();
831 }
832
833 void HeapShared::set_has_native_pointers(oop src_obj) {
834 CachedOopInfo* info = archived_object_cache()->get(src_obj);
835 assert(info != nullptr, "must be");
836 info->set_has_native_pointers();
837 }
838
839 // Between start_scanning_for_oops() and end_scanning_for_oops(), we discover all Java heap objects that
840 // should be stored in the AOT cache. The scanning is coordinated by AOTArtifactFinder.
841 void HeapShared::start_scanning_for_oops() {
842 {
843 NoSafepointVerifier nsv;
844
845 // The special subgraph doesn't belong to any class. We use Object_klass() here just
846 // for convenience.
847 _dump_time_special_subgraph = init_subgraph_info(vmClasses::Object_klass(), false);
848 _context = new GrowableArrayCHeap<const char*, mtClassShared>(250);
849
850 // Cache for recording where the archived objects are copied to
851 create_archived_object_cache();
852
853 if (UseCompressedOops || UseG1GC) {
854 log_info(cds)("Heap range = [" PTR_FORMAT " - " PTR_FORMAT "]",
855 UseCompressedOops ? p2i(CompressedOops::begin()) :
856 p2i((address)G1CollectedHeap::heap()->reserved().start()),
857 UseCompressedOops ? p2i(CompressedOops::end()) :
858 p2i((address)G1CollectedHeap::heap()->reserved().end()));
859 }
860
861 archive_subgraphs();
862 }
863
864 init_seen_objects_table();
865 Universe::archive_exception_instances();
866 }
867
868 void HeapShared::end_scanning_for_oops() {
869 archive_strings();
870 delete_seen_objects_table();
871 }
872
873 void HeapShared::write_heap(ArchiveHeapInfo *heap_info) {
874 {
875 NoSafepointVerifier nsv;
876 if (!SkipArchiveHeapVerification) {
877 CDSHeapVerifier::verify();
878 }
879 check_special_subgraph_classes();
880 }
881
882 StringTable::write_shared_table(_dumped_interned_strings);
883 GrowableArrayCHeap<oop, mtClassShared>* roots = new GrowableArrayCHeap<oop, mtClassShared>(_pending_roots->length());
884 for (int i = 0; i < _pending_roots->length(); i++) {
885 roots->append(_pending_roots->at(i).resolve());
886 }
887 ArchiveHeapWriter::write(roots, heap_info);
888 delete roots;
889
890 ArchiveBuilder::OtherROAllocMark mark;
891 write_subgraph_info_table();
892 }
893
894 void HeapShared::scan_java_mirror(oop orig_mirror) {
895 oop m = scratch_java_mirror(orig_mirror);
896 if (m != nullptr) { // nullptr if for custom class loader
897 copy_java_mirror_hashcode(orig_mirror, m);
898 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, m);
899 assert(success, "sanity");
900 }
901 }
902
903 void HeapShared::scan_java_class(Klass* orig_k) {
904 scan_java_mirror(orig_k->java_mirror());
905
906 if (orig_k->is_instance_klass()) {
907 InstanceKlass* orig_ik = InstanceKlass::cast(orig_k);
908 orig_ik->constants()->prepare_resolved_references_for_archiving();
909 objArrayOop rr = get_archived_resolved_references(orig_ik);
910 if (rr != nullptr) {
911 bool success = HeapShared::archive_reachable_objects_from(1, _dump_time_special_subgraph, rr);
912 assert(success, "must be");
913 }
914
915 orig_ik->constants()->add_dumped_interned_strings();
916 }
917 }
918
919 void HeapShared::archive_subgraphs() {
920 assert(CDSConfig::is_dumping_heap(), "must be");
921
922 archive_object_subgraphs(archive_subgraph_entry_fields,
923 false /* is_full_module_graph */);
924
925 if (CDSConfig::is_dumping_full_module_graph()) {
926 archive_object_subgraphs(fmg_archive_subgraph_entry_fields,
927 true /* is_full_module_graph */);
928 Modules::verify_archived_modules();
929 }
930 }
931
932 //
933 // Subgraph archiving support
934 //
935 HeapShared::DumpTimeKlassSubGraphInfoTable* HeapShared::_dump_time_subgraph_info_table = nullptr;
936 HeapShared::RunTimeKlassSubGraphInfoTable HeapShared::_run_time_subgraph_info_table;
937
938 // Get the subgraph_info for Klass k. A new subgraph_info is created if
939 // there is no existing one for k. The subgraph_info records the "buffered"
940 // address of the class.
941 KlassSubGraphInfo* HeapShared::init_subgraph_info(Klass* k, bool is_full_module_graph) {
942 assert(CDSConfig::is_dumping_heap(), "dump time only");
943 bool created;
944 KlassSubGraphInfo* info =
945 _dump_time_subgraph_info_table->put_if_absent(k, KlassSubGraphInfo(k, is_full_module_graph),
946 &created);
947 assert(created, "must not initialize twice");
948 return info;
949 }
950
951 KlassSubGraphInfo* HeapShared::get_subgraph_info(Klass* k) {
952 assert(CDSConfig::is_dumping_heap(), "dump time only");
953 KlassSubGraphInfo* info = _dump_time_subgraph_info_table->get(k);
954 assert(info != nullptr, "must have been initialized");
955 return info;
956 }
957
958 // Add an entry field to the current KlassSubGraphInfo.
959 void KlassSubGraphInfo::add_subgraph_entry_field(int static_field_offset, oop v) {
960 assert(CDSConfig::is_dumping_heap(), "dump time only");
961 if (_subgraph_entry_fields == nullptr) {
962 _subgraph_entry_fields =
963 new (mtClass) GrowableArray<int>(10, mtClass);
964 }
965 _subgraph_entry_fields->append(static_field_offset);
966 _subgraph_entry_fields->append(HeapShared::append_root(v));
967 }
968
969 // Add the Klass* for an object in the current KlassSubGraphInfo's subgraphs.
970 // Only objects of boot classes can be included in sub-graph.
971 void KlassSubGraphInfo::add_subgraph_object_klass(Klass* orig_k) {
972 assert(CDSConfig::is_dumping_heap(), "dump time only");
973
974 if (_subgraph_object_klasses == nullptr) {
975 _subgraph_object_klasses =
976 new (mtClass) GrowableArray<Klass*>(50, mtClass);
977 }
978
979 if (_k == orig_k) {
980 // Don't add the Klass containing the sub-graph to it's own klass
981 // initialization list.
982 return;
983 }
984
985 if (orig_k->is_instance_klass()) {
986 #ifdef ASSERT
987 InstanceKlass* ik = InstanceKlass::cast(orig_k);
988 if (CDSConfig::is_dumping_method_handles()) {
989 // -XX:AOTInitTestClass must be used carefully in regression tests to
990 // include only classes that are safe to aot-initialize.
991 assert(ik->class_loader() == nullptr ||
992 HeapShared::is_lambda_proxy_klass(ik) ||
993 AOTClassInitializer::has_test_class(),
994 "we can archive only instances of boot classes or lambda proxy classes");
995 } else {
996 assert(ik->class_loader() == nullptr, "must be boot class");
997 }
998 #endif
999 // vmClasses::xxx_klass() are not updated, need to check
1000 // the original Klass*
1001 if (orig_k == vmClasses::String_klass() ||
1002 orig_k == vmClasses::Object_klass()) {
1003 // Initialized early during VM initialization. No need to be added
1004 // to the sub-graph object class list.
1005 return;
1006 }
1007 check_allowed_klass(InstanceKlass::cast(orig_k));
1008 } else if (orig_k->is_objArray_klass()) {
1009 Klass* abk = ObjArrayKlass::cast(orig_k)->bottom_klass();
1010 if (abk->is_instance_klass()) {
1011 assert(InstanceKlass::cast(abk)->is_shared_boot_class(),
1012 "must be boot class");
1013 check_allowed_klass(InstanceKlass::cast(ObjArrayKlass::cast(orig_k)->bottom_klass()));
1014 }
1015 if (orig_k == Universe::objectArrayKlass()) {
1016 // Initialized early during Universe::genesis. No need to be added
1017 // to the list.
1018 return;
1019 }
1020 } else {
1021 assert(orig_k->is_typeArray_klass(), "must be");
1022 // Primitive type arrays are created early during Universe::genesis.
1023 return;
1024 }
1025
1026 if (log_is_enabled(Debug, cds, heap)) {
1027 if (!_subgraph_object_klasses->contains(orig_k)) {
1028 ResourceMark rm;
1029 log_debug(cds, heap)("Adding klass %s", orig_k->external_name());
1030 }
1031 }
1032
1033 _subgraph_object_klasses->append_if_missing(orig_k);
1034 _has_non_early_klasses |= is_non_early_klass(orig_k);
1035 }
1036
1037 void KlassSubGraphInfo::check_allowed_klass(InstanceKlass* ik) {
1038 #ifndef PRODUCT
1039 if (AOTClassInitializer::has_test_class()) {
1040 // The tests can cache arbitrary types of objects.
1041 return;
1042 }
1043 #endif
1044
1045 if (ik->module()->name() == vmSymbols::java_base()) {
1046 assert(ik->package() != nullptr, "classes in java.base cannot be in unnamed package");
1047 return;
1048 }
1049
1050 const char* lambda_msg = "";
1051 if (CDSConfig::is_dumping_method_handles()) {
1052 lambda_msg = ", or a lambda proxy class";
1053 if (HeapShared::is_lambda_proxy_klass(ik) &&
1054 (ik->class_loader() == nullptr ||
1055 ik->class_loader() == SystemDictionary::java_platform_loader() ||
1056 ik->class_loader() == SystemDictionary::java_system_loader())) {
1057 return;
1058 }
1059 }
1060
1061 #ifndef PRODUCT
1062 if (!ik->module()->is_named() && ik->package() == nullptr && ArchiveHeapTestClass != nullptr) {
1063 // This class is loaded by ArchiveHeapTestClass
1064 return;
1065 }
1066 const char* testcls_msg = ", or a test class in an unnamed package of an unnamed module";
1067 #else
1068 const char* testcls_msg = "";
1069 #endif
1070
1071 ResourceMark rm;
1072 log_error(cds, heap)("Class %s not allowed in archive heap. Must be in java.base%s%s",
1073 ik->external_name(), lambda_msg, testcls_msg);
1074 MetaspaceShared::unrecoverable_writing_error();
1075 }
1076
1077 bool KlassSubGraphInfo::is_non_early_klass(Klass* k) {
1078 if (k->is_objArray_klass()) {
1079 k = ObjArrayKlass::cast(k)->bottom_klass();
1080 }
1081 if (k->is_instance_klass()) {
1082 if (!SystemDictionaryShared::is_early_klass(InstanceKlass::cast(k))) {
1083 ResourceMark rm;
1084 log_info(cds, heap)("non-early: %s", k->external_name());
1085 return true;
1086 } else {
1087 return false;
1088 }
1089 } else {
1090 return false;
1091 }
1092 }
1093
1094 // Initialize an archived subgraph_info_record from the given KlassSubGraphInfo.
1095 void ArchivedKlassSubGraphInfoRecord::init(KlassSubGraphInfo* info) {
1096 _k = ArchiveBuilder::get_buffered_klass(info->klass());
1097 _entry_field_records = nullptr;
1098 _subgraph_object_klasses = nullptr;
1099 _is_full_module_graph = info->is_full_module_graph();
1100
1101 if (_is_full_module_graph) {
1102 // Consider all classes referenced by the full module graph as early -- we will be
1103 // allocating objects of these classes during JVMTI early phase, so they cannot
1104 // be processed by (non-early) JVMTI ClassFileLoadHook
1105 _has_non_early_klasses = false;
1106 } else {
1107 _has_non_early_klasses = info->has_non_early_klasses();
1108 }
1109
1110 if (_has_non_early_klasses) {
1111 ResourceMark rm;
1112 log_info(cds, heap)(
1113 "Subgraph of klass %s has non-early klasses and cannot be used when JVMTI ClassFileLoadHook is enabled",
1114 _k->external_name());
1115 }
1116
1117 // populate the entry fields
1118 GrowableArray<int>* entry_fields = info->subgraph_entry_fields();
1119 if (entry_fields != nullptr) {
1120 int num_entry_fields = entry_fields->length();
1121 assert(num_entry_fields % 2 == 0, "sanity");
1122 _entry_field_records =
1123 ArchiveBuilder::new_ro_array<int>(num_entry_fields);
1124 for (int i = 0 ; i < num_entry_fields; i++) {
1125 _entry_field_records->at_put(i, entry_fields->at(i));
1126 }
1127 }
1128
1129 // <recorded_klasses> has the Klasses of all the objects that are referenced by this subgraph.
1130 // Copy those that need to be explicitly initialized into <_subgraph_object_klasses>.
1131 GrowableArray<Klass*>* recorded_klasses = info->subgraph_object_klasses();
1132 if (recorded_klasses != nullptr) {
1133 // AOT-inited classes are automatically marked as "initialized" during bootstrap. When
1134 // programmatically loading a subgraph, we only need to explicitly initialize the classes
1135 // that are not aot-inited.
1136 int num_to_copy = 0;
1137 for (int i = 0; i < recorded_klasses->length(); i++) {
1138 Klass* subgraph_k = ArchiveBuilder::get_buffered_klass(recorded_klasses->at(i));
1139 if (!subgraph_k->has_aot_initialized_mirror()) {
1140 num_to_copy ++;
1141 }
1142 }
1143
1144 _subgraph_object_klasses = ArchiveBuilder::new_ro_array<Klass*>(num_to_copy);
1145 bool is_special = (_k == ArchiveBuilder::get_buffered_klass(vmClasses::Object_klass()));
1146 for (int i = 0, n = 0; i < recorded_klasses->length(); i++) {
1147 Klass* subgraph_k = ArchiveBuilder::get_buffered_klass(recorded_klasses->at(i));
1148 if (subgraph_k->has_aot_initialized_mirror()) {
1149 continue;
1150 }
1151 if (log_is_enabled(Info, cds, heap)) {
1152 ResourceMark rm;
1153 const char* owner_name = is_special ? "<special>" : _k->external_name();
1154 if (subgraph_k->is_instance_klass()) {
1155 InstanceKlass* src_ik = InstanceKlass::cast(ArchiveBuilder::current()->get_source_addr(subgraph_k));
1156 }
1157 log_info(cds, heap)(
1158 "Archived object klass %s (%2d) => %s",
1159 owner_name, n, subgraph_k->external_name());
1160 }
1161 _subgraph_object_klasses->at_put(n, subgraph_k);
1162 ArchivePtrMarker::mark_pointer(_subgraph_object_klasses->adr_at(n));
1163 n++;
1164 }
1165 }
1166
1167 ArchivePtrMarker::mark_pointer(&_k);
1168 ArchivePtrMarker::mark_pointer(&_entry_field_records);
1169 ArchivePtrMarker::mark_pointer(&_subgraph_object_klasses);
1170 }
1171
1172 class HeapShared::CopyKlassSubGraphInfoToArchive : StackObj {
1173 CompactHashtableWriter* _writer;
1174 public:
1175 CopyKlassSubGraphInfoToArchive(CompactHashtableWriter* writer) : _writer(writer) {}
1176
1177 bool do_entry(Klass* klass, KlassSubGraphInfo& info) {
1178 if (info.subgraph_object_klasses() != nullptr || info.subgraph_entry_fields() != nullptr) {
1179 ArchivedKlassSubGraphInfoRecord* record = HeapShared::archive_subgraph_info(&info);
1180 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(klass);
1181 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary((address)buffered_k);
1182 u4 delta = ArchiveBuilder::current()->any_to_offset_u4(record);
1183 _writer->add(hash, delta);
1184 }
1185 return true; // keep on iterating
1186 }
1187 };
1188
1189 ArchivedKlassSubGraphInfoRecord* HeapShared::archive_subgraph_info(KlassSubGraphInfo* info) {
1190 ArchivedKlassSubGraphInfoRecord* record =
1191 (ArchivedKlassSubGraphInfoRecord*)ArchiveBuilder::ro_region_alloc(sizeof(ArchivedKlassSubGraphInfoRecord));
1192 record->init(info);
1193 if (info == _dump_time_special_subgraph) {
1194 _run_time_special_subgraph = record;
1195 }
1196 return record;
1197 }
1198
1199 // Build the records of archived subgraph infos, which include:
1200 // - Entry points to all subgraphs from the containing class mirror. The entry
1201 // points are static fields in the mirror. For each entry point, the field
1202 // offset, and value are recorded in the sub-graph
1203 // info. The value is stored back to the corresponding field at runtime.
1204 // - A list of klasses that need to be loaded/initialized before archived
1205 // java object sub-graph can be accessed at runtime.
1206 void HeapShared::write_subgraph_info_table() {
1207 // Allocate the contents of the hashtable(s) inside the RO region of the CDS archive.
1208 DumpTimeKlassSubGraphInfoTable* d_table = _dump_time_subgraph_info_table;
1209 CompactHashtableStats stats;
1210
1211 _run_time_subgraph_info_table.reset();
1212
1213 CompactHashtableWriter writer(d_table->_count, &stats);
1214 CopyKlassSubGraphInfoToArchive copy(&writer);
1215 d_table->iterate(©);
1216 writer.dump(&_run_time_subgraph_info_table, "subgraphs");
1217
1218 #ifndef PRODUCT
1219 if (ArchiveHeapTestClass != nullptr) {
1220 size_t len = strlen(ArchiveHeapTestClass) + 1;
1221 Array<char>* array = ArchiveBuilder::new_ro_array<char>((int)len);
1222 strncpy(array->adr_at(0), ArchiveHeapTestClass, len);
1223 _archived_ArchiveHeapTestClass = array;
1224 }
1225 #endif
1226 if (log_is_enabled(Info, cds, heap)) {
1227 print_stats();
1228 }
1229 }
1230
1231 void HeapShared::add_root_segment(objArrayOop segment_oop) {
1232 assert(segment_oop != nullptr, "must be");
1233 assert(ArchiveHeapLoader::is_in_use(), "must be");
1234 if (_root_segments == nullptr) {
1235 _root_segments = new GrowableArrayCHeap<OopHandle, mtClassShared>(10);
1236 }
1237 _root_segments->push(OopHandle(Universe::vm_global(), segment_oop));
1238 }
1239
1240 void HeapShared::init_root_segment_sizes(int max_size_elems) {
1241 _root_segment_max_size_elems = max_size_elems;
1242 }
1243
1244 void HeapShared::serialize_tables(SerializeClosure* soc) {
1245
1246 #ifndef PRODUCT
1247 soc->do_ptr(&_archived_ArchiveHeapTestClass);
1248 if (soc->reading() && _archived_ArchiveHeapTestClass != nullptr) {
1249 _test_class_name = _archived_ArchiveHeapTestClass->adr_at(0);
1250 setup_test_class(_test_class_name);
1251 }
1252 #endif
1253
1254 _run_time_subgraph_info_table.serialize_header(soc);
1255 soc->do_ptr(&_run_time_special_subgraph);
1256 }
1257
1258 static void verify_the_heap(Klass* k, const char* which) {
1259 if (VerifyArchivedFields > 0) {
1260 ResourceMark rm;
1261 log_info(cds, heap)("Verify heap %s initializing static field(s) in %s",
1262 which, k->external_name());
1263
1264 VM_Verify verify_op;
1265 VMThread::execute(&verify_op);
1266
1267 if (VerifyArchivedFields > 1 && is_init_completed()) {
1268 // At this time, the oop->klass() of some archived objects in the heap may not
1269 // have been loaded into the system dictionary yet. Nevertheless, oop->klass() should
1270 // have enough information (object size, oop maps, etc) so that a GC can be safely
1271 // performed.
1272 //
1273 // -XX:VerifyArchivedFields=2 force a GC to happen in such an early stage
1274 // to check for GC safety.
1275 log_info(cds, heap)("Trigger GC %s initializing static field(s) in %s",
1276 which, k->external_name());
1277 FlagSetting fs1(VerifyBeforeGC, true);
1278 FlagSetting fs2(VerifyDuringGC, true);
1279 FlagSetting fs3(VerifyAfterGC, true);
1280 Universe::heap()->collect(GCCause::_java_lang_system_gc);
1281 }
1282 }
1283 }
1284
1285 // Before GC can execute, we must ensure that all oops reachable from HeapShared::roots()
1286 // have a valid klass. I.e., oopDesc::klass() must have already been resolved.
1287 //
1288 // Note: if a ArchivedKlassSubGraphInfoRecord contains non-early classes, and JVMTI
1289 // ClassFileLoadHook is enabled, it's possible for this class to be dynamically replaced. In
1290 // this case, we will not load the ArchivedKlassSubGraphInfoRecord and will clear its roots.
1291 void HeapShared::resolve_classes(JavaThread* current) {
1292 assert(CDSConfig::is_using_archive(), "runtime only!");
1293 if (!ArchiveHeapLoader::is_in_use()) {
1294 return; // nothing to do
1295 }
1296
1297 if (!CDSConfig::is_using_aot_linked_classes()) {
1298 assert( _run_time_special_subgraph != nullptr, "must be");
1299 Array<Klass*>* klasses = _run_time_special_subgraph->subgraph_object_klasses();
1300 if (klasses != nullptr) {
1301 for (int i = 0; i < klasses->length(); i++) {
1302 Klass* k = klasses->at(i);
1303 ExceptionMark em(current); // no exception can happen here
1304 resolve_or_init(k, /*do_init*/false, current);
1305 }
1306 }
1307 }
1308
1309 resolve_classes_for_subgraphs(current, archive_subgraph_entry_fields);
1310 resolve_classes_for_subgraphs(current, fmg_archive_subgraph_entry_fields);
1311 }
1312
1313 void HeapShared::resolve_classes_for_subgraphs(JavaThread* current, ArchivableStaticFieldInfo fields[]) {
1314 for (int i = 0; fields[i].valid(); i++) {
1315 ArchivableStaticFieldInfo* info = &fields[i];
1316 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
1317 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name);
1318 assert(k != nullptr && k->is_shared_boot_class(), "sanity");
1319 resolve_classes_for_subgraph_of(current, k);
1320 }
1321 }
1322
1323 void HeapShared::resolve_classes_for_subgraph_of(JavaThread* current, Klass* k) {
1324 JavaThread* THREAD = current;
1325 ExceptionMark em(THREAD);
1326 const ArchivedKlassSubGraphInfoRecord* record =
1327 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
1328 if (HAS_PENDING_EXCEPTION) {
1329 CLEAR_PENDING_EXCEPTION;
1330 }
1331 if (record == nullptr) {
1332 clear_archived_roots_of(k);
1333 }
1334 }
1335
1336 void HeapShared::initialize_java_lang_invoke(TRAPS) {
1337 if (CDSConfig::is_using_aot_linked_classes() || CDSConfig::is_dumping_method_handles()) {
1338 resolve_or_init("java/lang/invoke/Invokers$Holder", true, CHECK);
1339 resolve_or_init("java/lang/invoke/MethodHandle", true, CHECK);
1340 resolve_or_init("java/lang/invoke/MethodHandleNatives", true, CHECK);
1341 resolve_or_init("java/lang/invoke/DirectMethodHandle$Holder", true, CHECK);
1342 resolve_or_init("java/lang/invoke/DelegatingMethodHandle$Holder", true, CHECK);
1343 resolve_or_init("java/lang/invoke/LambdaForm$Holder", true, CHECK);
1344 resolve_or_init("java/lang/invoke/BoundMethodHandle$Species_L", true, CHECK);
1345 }
1346 }
1347
1348 // Initialize the InstanceKlasses of objects that are reachable from the following roots:
1349 // - interned strings
1350 // - Klass::java_mirror() -- including aot-initialized mirrors such as those of Enum klasses.
1351 // - ConstantPool::resolved_references()
1352 // - Universe::<xxx>_exception_instance()
1353 //
1354 // For example, if this enum class is initialized at AOT cache assembly time:
1355 //
1356 // enum Fruit {
1357 // APPLE, ORANGE, BANANA;
1358 // static final Set<Fruit> HAVE_SEEDS = new HashSet<>(Arrays.asList(APPLE, ORANGE));
1359 // }
1360 //
1361 // the aot-initialized mirror of Fruit has a static field that references HashSet, which
1362 // should be initialized before any Java code can access the Fruit class. Note that
1363 // HashSet itself doesn't necessary need to be an aot-initialized class.
1364 void HeapShared::init_classes_for_special_subgraph(Handle class_loader, TRAPS) {
1365 if (!ArchiveHeapLoader::is_in_use()) {
1366 return;
1367 }
1368
1369 assert( _run_time_special_subgraph != nullptr, "must be");
1370 Array<Klass*>* klasses = _run_time_special_subgraph->subgraph_object_klasses();
1371 if (klasses != nullptr) {
1372 for (int pass = 0; pass < 2; pass ++) {
1373 for (int i = 0; i < klasses->length(); i++) {
1374 Klass* k = klasses->at(i);
1375 if (k->class_loader_data() == nullptr) {
1376 // This class is not yet loaded. We will initialize it in a later phase.
1377 // For example, we have loaded only AOTLinkedClassCategory::BOOT1 classes
1378 // but k is part of AOTLinkedClassCategory::BOOT2.
1379 continue;
1380 }
1381 if (k->class_loader() == class_loader()) {
1382 if (pass == 0) {
1383 if (k->is_instance_klass()) {
1384 InstanceKlass::cast(k)->link_class(CHECK);
1385 }
1386 } else {
1387 resolve_or_init(k, /*do_init*/true, CHECK);
1388 }
1389 }
1390 }
1391 }
1392 }
1393 }
1394
1395 void HeapShared::initialize_from_archived_subgraph(JavaThread* current, Klass* k) {
1396 JavaThread* THREAD = current;
1397 if (!ArchiveHeapLoader::is_in_use()) {
1398 return; // nothing to do
1399 }
1400
1401 if (k->name()->equals("jdk/internal/module/ArchivedModuleGraph") &&
1402 !CDSConfig::is_using_optimized_module_handling() &&
1403 // archive was created with --module-path
1404 AOTClassLocationConfig::runtime()->num_module_paths() > 0) {
1405 // ArchivedModuleGraph was created with a --module-path that's different than the runtime --module-path.
1406 // Thus, it might contain references to modules that do not exist at runtime. We cannot use it.
1407 log_info(cds, heap)("Skip initializing ArchivedModuleGraph subgraph: is_using_optimized_module_handling=%s num_module_paths=%d",
1408 BOOL_TO_STR(CDSConfig::is_using_optimized_module_handling()),
1409 AOTClassLocationConfig::runtime()->num_module_paths());
1410 return;
1411 }
1412
1413 ExceptionMark em(THREAD);
1414 const ArchivedKlassSubGraphInfoRecord* record =
1415 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
1416
1417 if (HAS_PENDING_EXCEPTION) {
1418 CLEAR_PENDING_EXCEPTION;
1419 // None of the field value will be set if there was an exception when initializing the classes.
1420 // The java code will not see any of the archived objects in the
1421 // subgraphs referenced from k in this case.
1422 return;
1423 }
1424
1425 if (record != nullptr) {
1426 init_archived_fields_for(k, record);
1427 }
1428 }
1429
1430 const ArchivedKlassSubGraphInfoRecord*
1431 HeapShared::resolve_or_init_classes_for_subgraph_of(Klass* k, bool do_init, TRAPS) {
1432 assert(!CDSConfig::is_dumping_heap(), "Should not be called when dumping heap");
1433
1434 if (!k->is_shared()) {
1435 return nullptr;
1436 }
1437 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1438 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1439
1440 #ifndef PRODUCT
1441 if (_test_class_name != nullptr && k->name()->equals(_test_class_name) && record != nullptr) {
1442 _test_class = k;
1443 _test_class_record = record;
1444 }
1445 #endif
1446
1447 // Initialize from archived data. Currently this is done only
1448 // during VM initialization time. No lock is needed.
1449 if (record == nullptr) {
1450 if (log_is_enabled(Info, cds, heap)) {
1451 ResourceMark rm(THREAD);
1452 log_info(cds, heap)("subgraph %s is not recorded",
1453 k->external_name());
1454 }
1455 return nullptr;
1456 } else {
1457 if (record->is_full_module_graph() && !CDSConfig::is_using_full_module_graph()) {
1458 if (log_is_enabled(Info, cds, heap)) {
1459 ResourceMark rm(THREAD);
1460 log_info(cds, heap)("subgraph %s cannot be used because full module graph is disabled",
1461 k->external_name());
1462 }
1463 return nullptr;
1464 }
1465
1466 if (record->has_non_early_klasses() && JvmtiExport::should_post_class_file_load_hook()) {
1467 if (log_is_enabled(Info, cds, heap)) {
1468 ResourceMark rm(THREAD);
1469 log_info(cds, heap)("subgraph %s cannot be used because JVMTI ClassFileLoadHook is enabled",
1470 k->external_name());
1471 }
1472 return nullptr;
1473 }
1474
1475 if (log_is_enabled(Info, cds, heap)) {
1476 ResourceMark rm;
1477 log_info(cds, heap)("%s subgraph %s ", do_init ? "init" : "resolve", k->external_name());
1478 }
1479
1480 resolve_or_init(k, do_init, CHECK_NULL);
1481
1482 // Load/link/initialize the klasses of the objects in the subgraph.
1483 // nullptr class loader is used.
1484 Array<Klass*>* klasses = record->subgraph_object_klasses();
1485 if (klasses != nullptr) {
1486 for (int i = 0; i < klasses->length(); i++) {
1487 Klass* klass = klasses->at(i);
1488 if (!klass->is_shared()) {
1489 return nullptr;
1490 }
1491 resolve_or_init(klass, do_init, CHECK_NULL);
1492 }
1493 }
1494 }
1495
1496 return record;
1497 }
1498
1499 void HeapShared::resolve_or_init(const char* klass_name, bool do_init, TRAPS) {
1500 TempNewSymbol klass_name_sym = SymbolTable::new_symbol(klass_name);
1501 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name_sym);
1502 if (k == nullptr) {
1503 return;
1504 }
1505 assert(k->is_shared_boot_class(), "sanity");
1506 resolve_or_init(k, false, CHECK);
1507 if (do_init) {
1508 resolve_or_init(k, true, CHECK);
1509 }
1510 }
1511
1512 void HeapShared::resolve_or_init(Klass* k, bool do_init, TRAPS) {
1513 if (!do_init) {
1514 if (k->class_loader_data() == nullptr) {
1515 Klass* resolved_k = SystemDictionary::resolve_or_null(k->name(), CHECK);
1516 assert(resolved_k == k, "classes used by archived heap must not be replaced by JVMTI ClassFileLoadHook");
1517 }
1518 } else {
1519 assert(k->class_loader_data() != nullptr, "must have been resolved by HeapShared::resolve_classes");
1520 if (k->is_instance_klass()) {
1521 InstanceKlass* ik = InstanceKlass::cast(k);
1522 ik->initialize(CHECK);
1523 } else if (k->is_objArray_klass()) {
1524 ObjArrayKlass* oak = ObjArrayKlass::cast(k);
1525 oak->initialize(CHECK);
1526 }
1527 }
1528 }
1529
1530 void HeapShared::init_archived_fields_for(Klass* k, const ArchivedKlassSubGraphInfoRecord* record) {
1531 verify_the_heap(k, "before");
1532
1533 // Load the subgraph entry fields from the record and store them back to
1534 // the corresponding fields within the mirror.
1535 oop m = k->java_mirror();
1536 Array<int>* entry_field_records = record->entry_field_records();
1537 if (entry_field_records != nullptr) {
1538 int efr_len = entry_field_records->length();
1539 assert(efr_len % 2 == 0, "sanity");
1540 for (int i = 0; i < efr_len; i += 2) {
1541 int field_offset = entry_field_records->at(i);
1542 int root_index = entry_field_records->at(i+1);
1543 oop v = get_root(root_index, /*clear=*/true);
1544 if (k->has_aot_initialized_mirror()) {
1545 assert(v == m->obj_field(field_offset), "must be aot-initialized");
1546 } else {
1547 m->obj_field_put(field_offset, v);
1548 }
1549 log_debug(cds, heap)(" " PTR_FORMAT " init field @ %2d = " PTR_FORMAT, p2i(k), field_offset, p2i(v));
1550 }
1551
1552 // Done. Java code can see the archived sub-graphs referenced from k's
1553 // mirror after this point.
1554 if (log_is_enabled(Info, cds, heap)) {
1555 ResourceMark rm;
1556 log_info(cds, heap)("initialize_from_archived_subgraph %s " PTR_FORMAT "%s%s",
1557 k->external_name(), p2i(k), JvmtiExport::is_early_phase() ? " (early)" : "",
1558 k->has_aot_initialized_mirror() ? " (aot-inited)" : "");
1559 }
1560 }
1561
1562 verify_the_heap(k, "after ");
1563 }
1564
1565 void HeapShared::clear_archived_roots_of(Klass* k) {
1566 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1567 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1568 if (record != nullptr) {
1569 Array<int>* entry_field_records = record->entry_field_records();
1570 if (entry_field_records != nullptr) {
1571 int efr_len = entry_field_records->length();
1572 assert(efr_len % 2 == 0, "sanity");
1573 for (int i = 0; i < efr_len; i += 2) {
1574 int root_index = entry_field_records->at(i+1);
1575 clear_root(root_index);
1576 }
1577 }
1578 }
1579 }
1580
1581 // Push all oops that are referenced by _referencing_obj onto the _stack.
1582 class HeapShared::ReferentPusher: public BasicOopIterateClosure {
1583 PendingOopStack* _stack;
1584 GrowableArray<oop> _found_oop_fields;
1585 int _level;
1586 bool _record_klasses_only;
1587 KlassSubGraphInfo* _subgraph_info;
1588 oop _referencing_obj;
1589 public:
1590 ReferentPusher(PendingOopStack* stack,
1591 int level,
1592 bool record_klasses_only,
1593 KlassSubGraphInfo* subgraph_info,
1594 oop orig) :
1595 _stack(stack),
1596 _found_oop_fields(),
1597 _level(level),
1598 _record_klasses_only(record_klasses_only),
1599 _subgraph_info(subgraph_info),
1600 _referencing_obj(orig) {
1601 }
1602 void do_oop(narrowOop *p) { ReferentPusher::do_oop_work(p); }
1603 void do_oop( oop *p) { ReferentPusher::do_oop_work(p); }
1604
1605 ~ReferentPusher() {
1606 while (_found_oop_fields.length() > 0) {
1607 // This produces the exact same traversal order as the previous version
1608 // of ReferentPusher that recurses on the C stack -- a depth-first search,
1609 // walking the oop fields in _referencing_obj by ascending field offsets.
1610 oop obj = _found_oop_fields.pop();
1611 _stack->push(PendingOop(obj, _referencing_obj, _level + 1));
1612 }
1613 }
1614
1615 protected:
1616 template <class T> void do_oop_work(T *p) {
1617 oop obj = RawAccess<>::oop_load(p);
1618 if (!CompressedOops::is_null(obj)) {
1619 size_t field_delta = pointer_delta(p, _referencing_obj, sizeof(char));
1620
1621 if (!_record_klasses_only && log_is_enabled(Debug, cds, heap)) {
1622 ResourceMark rm;
1623 log_debug(cds, heap)("(%d) %s[%zu] ==> " PTR_FORMAT " size %zu %s", _level,
1624 _referencing_obj->klass()->external_name(), field_delta,
1625 p2i(obj), obj->size() * HeapWordSize, obj->klass()->external_name());
1626 if (log_is_enabled(Trace, cds, heap)) {
1627 LogTarget(Trace, cds, heap) log;
1628 LogStream out(log);
1629 obj->print_on(&out);
1630 }
1631 }
1632
1633 _found_oop_fields.push(obj);
1634 }
1635 }
1636
1637 public:
1638 oop referencing_obj() { return _referencing_obj; }
1639 KlassSubGraphInfo* subgraph_info() { return _subgraph_info; }
1640 };
1641
1642 // Checks if an oop has any non-null oop fields
1643 class PointsToOopsChecker : public BasicOopIterateClosure {
1644 bool _result;
1645
1646 template <class T> void check(T *p) {
1647 _result |= (HeapAccess<>::oop_load(p) != nullptr);
1648 }
1649
1650 public:
1651 PointsToOopsChecker() : _result(false) {}
1652 void do_oop(narrowOop *p) { check(p); }
1653 void do_oop( oop *p) { check(p); }
1654 bool result() { return _result; }
1655 };
1656
1657 HeapShared::CachedOopInfo HeapShared::make_cached_oop_info(oop obj, oop referrer) {
1658 PointsToOopsChecker points_to_oops_checker;
1659 obj->oop_iterate(&points_to_oops_checker);
1660 return CachedOopInfo(referrer, points_to_oops_checker.result());
1661 }
1662
1663 void HeapShared::init_box_classes(TRAPS) {
1664 if (ArchiveHeapLoader::is_in_use()) {
1665 vmClasses::Boolean_klass()->initialize(CHECK);
1666 vmClasses::Character_klass()->initialize(CHECK);
1667 vmClasses::Float_klass()->initialize(CHECK);
1668 vmClasses::Double_klass()->initialize(CHECK);
1669 vmClasses::Byte_klass()->initialize(CHECK);
1670 vmClasses::Short_klass()->initialize(CHECK);
1671 vmClasses::Integer_klass()->initialize(CHECK);
1672 vmClasses::Long_klass()->initialize(CHECK);
1673 vmClasses::Void_klass()->initialize(CHECK);
1674 }
1675 }
1676
1677 void HeapShared::exit_on_error() {
1678 if (_context != nullptr) {
1679 ResourceMark rm;
1680 LogStream ls(Log(cds, heap)::error());
1681 ls.print_cr("Context");
1682 for (int i = 0; i < _context->length(); i++) {
1683 const char* s = _context->at(i);
1684 ls.print_cr("- %s", s);
1685 }
1686 }
1687 debug_trace();
1688 MetaspaceShared::unrecoverable_writing_error();
1689 }
1690
1691 // (1) If orig_obj has not been archived yet, archive it.
1692 // (2) If orig_obj has not been seen yet (since start_recording_subgraph() was called),
1693 // trace all objects that are reachable from it, and make sure these objects are archived.
1694 // (3) Record the klasses of all objects that are reachable from orig_obj (including those that
1695 // were already archived when this function is called)
1696 bool HeapShared::archive_reachable_objects_from(int level,
1697 KlassSubGraphInfo* subgraph_info,
1698 oop orig_obj) {
1699 assert(orig_obj != nullptr, "must be");
1700 PendingOopStack stack;
1701 stack.push(PendingOop(orig_obj, nullptr, level));
1702
1703 while (stack.length() > 0) {
1704 PendingOop po = stack.pop();
1705 _object_being_archived = po;
1706 bool status = walk_one_object(&stack, po.level(), subgraph_info, po.obj(), po.referrer());
1707 _object_being_archived = PendingOop();
1708
1709 if (!status) {
1710 // Don't archive a subgraph root that's too big. For archives static fields, that's OK
1711 // as the Java code will take care of initializing this field dynamically.
1712 assert(level == 1, "VM should have exited with unarchivable objects for _level > 1");
1713 return false;
1714 }
1715 }
1716
1717 return true;
1718 }
1719
1720 bool HeapShared::walk_one_object(PendingOopStack* stack, int level, KlassSubGraphInfo* subgraph_info,
1721 oop orig_obj, oop referrer) {
1722 assert(orig_obj != nullptr, "must be");
1723 if (!JavaClasses::is_supported_for_archiving(orig_obj)) {
1724 // This object has injected fields that cannot be supported easily, so we disallow them for now.
1725 // If you get an error here, you probably made a change in the JDK library that has added
1726 // these objects that are referenced (directly or indirectly) by static fields.
1727 ResourceMark rm;
1728 log_error(cds, heap)("Cannot archive object " PTR_FORMAT " of class %s", p2i(orig_obj), orig_obj->klass()->external_name());
1729 exit_on_error();
1730 }
1731
1732 if (log_is_enabled(Debug, cds, heap) && java_lang_Class::is_instance(orig_obj)) {
1733 ResourceMark rm;
1734 LogTarget(Debug, cds, heap) log;
1735 LogStream out(log);
1736 out.print("Found java mirror " PTR_FORMAT " ", p2i(orig_obj));
1737 Klass* k = java_lang_Class::as_Klass(orig_obj);
1738 if (k != nullptr) {
1739 out.print("%s", k->external_name());
1740 } else {
1741 out.print("primitive");
1742 }
1743 out.print_cr("; scratch mirror = " PTR_FORMAT,
1744 p2i(scratch_java_mirror(orig_obj)));
1745 }
1746
1747 if (CDSConfig::is_initing_classes_at_dump_time()) {
1748 if (java_lang_Class::is_instance(orig_obj)) {
1749 orig_obj = scratch_java_mirror(orig_obj);
1750 assert(orig_obj != nullptr, "must be archived");
1751 }
1752 } else if (java_lang_Class::is_instance(orig_obj) && subgraph_info != _dump_time_special_subgraph) {
1753 // Without CDSConfig::is_initing_classes_at_dump_time(), we only allow archived objects to
1754 // point to the mirrors of (1) j.l.Object, (2) primitive classes, and (3) box classes. These are initialized
1755 // very early by HeapShared::init_box_classes().
1756 if (orig_obj == vmClasses::Object_klass()->java_mirror()
1757 || java_lang_Class::is_primitive(orig_obj)
1758 || orig_obj == vmClasses::Boolean_klass()->java_mirror()
1759 || orig_obj == vmClasses::Character_klass()->java_mirror()
1760 || orig_obj == vmClasses::Float_klass()->java_mirror()
1761 || orig_obj == vmClasses::Double_klass()->java_mirror()
1762 || orig_obj == vmClasses::Byte_klass()->java_mirror()
1763 || orig_obj == vmClasses::Short_klass()->java_mirror()
1764 || orig_obj == vmClasses::Integer_klass()->java_mirror()
1765 || orig_obj == vmClasses::Long_klass()->java_mirror()
1766 || orig_obj == vmClasses::Void_klass()->java_mirror()) {
1767 orig_obj = scratch_java_mirror(orig_obj);
1768 assert(orig_obj != nullptr, "must be archived");
1769 } else {
1770 // If you get an error here, you probably made a change in the JDK library that has added a Class
1771 // object that is referenced (directly or indirectly) by an ArchivableStaticFieldInfo
1772 // defined at the top of this file.
1773 log_error(cds, heap)("(%d) Unknown java.lang.Class object is in the archived sub-graph", level);
1774 debug_trace();
1775 MetaspaceShared::unrecoverable_writing_error();
1776 }
1777 }
1778
1779 if (has_been_seen_during_subgraph_recording(orig_obj)) {
1780 // orig_obj has already been archived and traced. Nothing more to do.
1781 return true;
1782 } else {
1783 set_has_been_seen_during_subgraph_recording(orig_obj);
1784 }
1785
1786 bool already_archived = has_been_archived(orig_obj);
1787 bool record_klasses_only = already_archived;
1788 if (!already_archived) {
1789 ++_num_new_archived_objs;
1790 if (!archive_object(orig_obj, referrer, subgraph_info)) {
1791 // Skip archiving the sub-graph referenced from the current entry field.
1792 ResourceMark rm;
1793 log_error(cds, heap)(
1794 "Cannot archive the sub-graph referenced from %s object ("
1795 PTR_FORMAT ") size %zu, skipped.",
1796 orig_obj->klass()->external_name(), p2i(orig_obj), orig_obj->size() * HeapWordSize);
1797 if (level == 1) {
1798 // Don't archive a subgraph root that's too big. For archives static fields, that's OK
1799 // as the Java code will take care of initializing this field dynamically.
1800 return false;
1801 } else {
1802 // We don't know how to handle an object that has been archived, but some of its reachable
1803 // objects cannot be archived. Bail out for now. We might need to fix this in the future if
1804 // we have a real use case.
1805 exit_on_error();
1806 }
1807 }
1808 }
1809
1810 Klass *orig_k = orig_obj->klass();
1811 subgraph_info->add_subgraph_object_klass(orig_k);
1812
1813 {
1814 // Find all the oops that are referenced by orig_obj, push them onto the stack
1815 // so we can work on them next.
1816 ResourceMark rm;
1817 ReferentPusher pusher(stack, level, record_klasses_only, subgraph_info, orig_obj);
1818 orig_obj->oop_iterate(&pusher);
1819 }
1820
1821 if (CDSConfig::is_initing_classes_at_dump_time()) {
1822 // The enum klasses are archived with aot-initialized mirror.
1823 // See AOTClassInitializer::can_archive_initialized_mirror().
1824 } else {
1825 if (CDSEnumKlass::is_enum_obj(orig_obj)) {
1826 CDSEnumKlass::handle_enum_obj(level + 1, subgraph_info, orig_obj);
1827 }
1828 }
1829
1830 return true;
1831 }
1832
1833 //
1834 // Start from the given static field in a java mirror and archive the
1835 // complete sub-graph of java heap objects that are reached directly
1836 // or indirectly from the starting object by following references.
1837 // Sub-graph archiving restrictions (current):
1838 //
1839 // - All classes of objects in the archived sub-graph (including the
1840 // entry class) must be boot class only.
1841 // - No java.lang.Class instance (java mirror) can be included inside
1842 // an archived sub-graph. Mirror can only be the sub-graph entry object.
1843 //
1844 // The Java heap object sub-graph archiving process (see ReferentPusher):
1845 //
1846 // 1) Java object sub-graph archiving starts from a given static field
1847 // within a Class instance (java mirror). If the static field is a
1848 // reference field and points to a non-null java object, proceed to
1849 // the next step.
1850 //
1851 // 2) Archives the referenced java object. If an archived copy of the
1852 // current object already exists, updates the pointer in the archived
1853 // copy of the referencing object to point to the current archived object.
1854 // Otherwise, proceed to the next step.
1855 //
1856 // 3) Follows all references within the current java object and recursively
1857 // archive the sub-graph of objects starting from each reference.
1858 //
1859 // 4) Updates the pointer in the archived copy of referencing object to
1860 // point to the current archived object.
1861 //
1862 // 5) The Klass of the current java object is added to the list of Klasses
1863 // for loading and initializing before any object in the archived graph can
1864 // be accessed at runtime.
1865 //
1866 void HeapShared::archive_reachable_objects_from_static_field(InstanceKlass *k,
1867 const char* klass_name,
1868 int field_offset,
1869 const char* field_name) {
1870 assert(CDSConfig::is_dumping_heap(), "dump time only");
1871 assert(k->is_shared_boot_class(), "must be boot class");
1872
1873 oop m = k->java_mirror();
1874
1875 KlassSubGraphInfo* subgraph_info = get_subgraph_info(k);
1876 oop f = m->obj_field(field_offset);
1877
1878 log_debug(cds, heap)("Start archiving from: %s::%s (" PTR_FORMAT ")", klass_name, field_name, p2i(f));
1879
1880 if (!CompressedOops::is_null(f)) {
1881 if (log_is_enabled(Trace, cds, heap)) {
1882 LogTarget(Trace, cds, heap) log;
1883 LogStream out(log);
1884 f->print_on(&out);
1885 }
1886
1887 bool success = archive_reachable_objects_from(1, subgraph_info, f);
1888 if (!success) {
1889 log_error(cds, heap)("Archiving failed %s::%s (some reachable objects cannot be archived)",
1890 klass_name, field_name);
1891 } else {
1892 // Note: the field value is not preserved in the archived mirror.
1893 // Record the field as a new subGraph entry point. The recorded
1894 // information is restored from the archive at runtime.
1895 subgraph_info->add_subgraph_entry_field(field_offset, f);
1896 log_info(cds, heap)("Archived field %s::%s => " PTR_FORMAT, klass_name, field_name, p2i(f));
1897 }
1898 } else {
1899 // The field contains null, we still need to record the entry point,
1900 // so it can be restored at runtime.
1901 subgraph_info->add_subgraph_entry_field(field_offset, nullptr);
1902 }
1903 }
1904
1905 #ifndef PRODUCT
1906 class VerifySharedOopClosure: public BasicOopIterateClosure {
1907 public:
1908 void do_oop(narrowOop *p) { VerifySharedOopClosure::do_oop_work(p); }
1909 void do_oop( oop *p) { VerifySharedOopClosure::do_oop_work(p); }
1910
1911 protected:
1912 template <class T> void do_oop_work(T *p) {
1913 oop obj = RawAccess<>::oop_load(p);
1914 if (!CompressedOops::is_null(obj)) {
1915 HeapShared::verify_reachable_objects_from(obj);
1916 }
1917 }
1918 };
1919
1920 void HeapShared::verify_subgraph_from_static_field(InstanceKlass* k, int field_offset) {
1921 assert(CDSConfig::is_dumping_heap(), "dump time only");
1922 assert(k->is_shared_boot_class(), "must be boot class");
1923
1924 oop m = k->java_mirror();
1925 oop f = m->obj_field(field_offset);
1926 if (!CompressedOops::is_null(f)) {
1927 verify_subgraph_from(f);
1928 }
1929 }
1930
1931 void HeapShared::verify_subgraph_from(oop orig_obj) {
1932 if (!has_been_archived(orig_obj)) {
1933 // It's OK for the root of a subgraph to be not archived. See comments in
1934 // archive_reachable_objects_from().
1935 return;
1936 }
1937
1938 // Verify that all objects reachable from orig_obj are archived.
1939 init_seen_objects_table();
1940 verify_reachable_objects_from(orig_obj);
1941 delete_seen_objects_table();
1942 }
1943
1944 void HeapShared::verify_reachable_objects_from(oop obj) {
1945 _num_total_verifications ++;
1946 if (java_lang_Class::is_instance(obj)) {
1947 obj = scratch_java_mirror(obj);
1948 assert(obj != nullptr, "must be");
1949 }
1950 if (!has_been_seen_during_subgraph_recording(obj)) {
1951 set_has_been_seen_during_subgraph_recording(obj);
1952 assert(has_been_archived(obj), "must be");
1953 VerifySharedOopClosure walker;
1954 obj->oop_iterate(&walker);
1955 }
1956 }
1957 #endif
1958
1959 void HeapShared::check_special_subgraph_classes() {
1960 if (CDSConfig::is_initing_classes_at_dump_time()) {
1961 // We can have aot-initialized classes (such as Enums) that can reference objects
1962 // of arbitrary types. Currently, we trust the JEP 483 implementation to only
1963 // aot-initialize classes that are "safe".
1964 //
1965 // TODO: we need an automatic tool that checks the safety of aot-initialized
1966 // classes (when we extend the set of aot-initialized classes beyond JEP 483)
1967 return;
1968 } else {
1969 // In this case, the special subgraph should contain a few specific types
1970 GrowableArray<Klass*>* klasses = _dump_time_special_subgraph->subgraph_object_klasses();
1971 int num = klasses->length();
1972 for (int i = 0; i < num; i++) {
1973 Klass* subgraph_k = klasses->at(i);
1974 Symbol* name = subgraph_k->name();
1975 if (subgraph_k->is_instance_klass() &&
1976 name != vmSymbols::java_lang_Class() &&
1977 name != vmSymbols::java_lang_String() &&
1978 name != vmSymbols::java_lang_ArithmeticException() &&
1979 name != vmSymbols::java_lang_ArrayIndexOutOfBoundsException() &&
1980 name != vmSymbols::java_lang_ArrayStoreException() &&
1981 name != vmSymbols::java_lang_ClassCastException() &&
1982 name != vmSymbols::java_lang_InternalError() &&
1983 name != vmSymbols::java_lang_NullPointerException()) {
1984 ResourceMark rm;
1985 fatal("special subgraph cannot have objects of type %s", subgraph_k->external_name());
1986 }
1987 }
1988 }
1989 }
1990
1991 HeapShared::SeenObjectsTable* HeapShared::_seen_objects_table = nullptr;
1992 HeapShared::PendingOop HeapShared::_object_being_archived;
1993 int HeapShared::_num_new_walked_objs;
1994 int HeapShared::_num_new_archived_objs;
1995 int HeapShared::_num_old_recorded_klasses;
1996
1997 int HeapShared::_num_total_subgraph_recordings = 0;
1998 int HeapShared::_num_total_walked_objs = 0;
1999 int HeapShared::_num_total_archived_objs = 0;
2000 int HeapShared::_num_total_recorded_klasses = 0;
2001 int HeapShared::_num_total_verifications = 0;
2002
2003 bool HeapShared::has_been_seen_during_subgraph_recording(oop obj) {
2004 return _seen_objects_table->get(obj) != nullptr;
2005 }
2006
2007 void HeapShared::set_has_been_seen_during_subgraph_recording(oop obj) {
2008 assert(!has_been_seen_during_subgraph_recording(obj), "sanity");
2009 _seen_objects_table->put_when_absent(obj, true);
2010 _seen_objects_table->maybe_grow();
2011 ++ _num_new_walked_objs;
2012 }
2013
2014 void HeapShared::start_recording_subgraph(InstanceKlass *k, const char* class_name, bool is_full_module_graph) {
2015 log_info(cds, heap)("Start recording subgraph(s) for archived fields in %s", class_name);
2016 init_subgraph_info(k, is_full_module_graph);
2017 init_seen_objects_table();
2018 _num_new_walked_objs = 0;
2019 _num_new_archived_objs = 0;
2020 _num_old_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses();
2021 }
2022
2023 void HeapShared::done_recording_subgraph(InstanceKlass *k, const char* class_name) {
2024 int num_new_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses() -
2025 _num_old_recorded_klasses;
2026 log_info(cds, heap)("Done recording subgraph(s) for archived fields in %s: "
2027 "walked %d objs, archived %d new objs, recorded %d classes",
2028 class_name, _num_new_walked_objs, _num_new_archived_objs,
2029 num_new_recorded_klasses);
2030
2031 delete_seen_objects_table();
2032
2033 _num_total_subgraph_recordings ++;
2034 _num_total_walked_objs += _num_new_walked_objs;
2035 _num_total_archived_objs += _num_new_archived_objs;
2036 _num_total_recorded_klasses += num_new_recorded_klasses;
2037 }
2038
2039 class ArchivableStaticFieldFinder: public FieldClosure {
2040 InstanceKlass* _ik;
2041 Symbol* _field_name;
2042 bool _found;
2043 int _offset;
2044 public:
2045 ArchivableStaticFieldFinder(InstanceKlass* ik, Symbol* field_name) :
2046 _ik(ik), _field_name(field_name), _found(false), _offset(-1) {}
2047
2048 virtual void do_field(fieldDescriptor* fd) {
2049 if (fd->name() == _field_name) {
2050 assert(!_found, "fields can never be overloaded");
2051 if (is_reference_type(fd->field_type())) {
2052 _found = true;
2053 _offset = fd->offset();
2054 }
2055 }
2056 }
2057 bool found() { return _found; }
2058 int offset() { return _offset; }
2059 };
2060
2061 void HeapShared::init_subgraph_entry_fields(ArchivableStaticFieldInfo fields[],
2062 TRAPS) {
2063 for (int i = 0; fields[i].valid(); i++) {
2064 ArchivableStaticFieldInfo* info = &fields[i];
2065 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
2066 TempNewSymbol field_name = SymbolTable::new_symbol(info->field_name);
2067 ResourceMark rm; // for stringStream::as_string() etc.
2068
2069 #ifndef PRODUCT
2070 bool is_test_class = (ArchiveHeapTestClass != nullptr) && (strcmp(info->klass_name, ArchiveHeapTestClass) == 0);
2071 const char* test_class_name = ArchiveHeapTestClass;
2072 #else
2073 bool is_test_class = false;
2074 const char* test_class_name = ""; // avoid C++ printf checks warnings.
2075 #endif
2076
2077 if (is_test_class) {
2078 log_warning(cds)("Loading ArchiveHeapTestClass %s ...", test_class_name);
2079 }
2080
2081 Klass* k = SystemDictionary::resolve_or_fail(klass_name, true, THREAD);
2082 if (HAS_PENDING_EXCEPTION) {
2083 CLEAR_PENDING_EXCEPTION;
2084 stringStream st;
2085 st.print("Fail to initialize archive heap: %s cannot be loaded by the boot loader", info->klass_name);
2086 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2087 }
2088
2089 if (!k->is_instance_klass()) {
2090 stringStream st;
2091 st.print("Fail to initialize archive heap: %s is not an instance class", info->klass_name);
2092 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2093 }
2094
2095 InstanceKlass* ik = InstanceKlass::cast(k);
2096 assert(InstanceKlass::cast(ik)->is_shared_boot_class(),
2097 "Only support boot classes");
2098
2099 if (is_test_class) {
2100 if (ik->module()->is_named()) {
2101 // We don't want ArchiveHeapTestClass to be abused to easily load/initialize arbitrary
2102 // core-lib classes. You need to at least append to the bootclasspath.
2103 stringStream st;
2104 st.print("ArchiveHeapTestClass %s is not in unnamed module", test_class_name);
2105 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2106 }
2107
2108 if (ik->package() != nullptr) {
2109 // This restriction makes HeapShared::is_a_test_class_in_unnamed_module() easy.
2110 stringStream st;
2111 st.print("ArchiveHeapTestClass %s is not in unnamed package", test_class_name);
2112 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2113 }
2114 } else {
2115 if (ik->module()->name() != vmSymbols::java_base()) {
2116 // We don't want to deal with cases when a module is unavailable at runtime.
2117 // FUTURE -- load from archived heap only when module graph has not changed
2118 // between dump and runtime.
2119 stringStream st;
2120 st.print("%s is not in java.base module", info->klass_name);
2121 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2122 }
2123 }
2124
2125 if (is_test_class) {
2126 log_warning(cds)("Initializing ArchiveHeapTestClass %s ...", test_class_name);
2127 }
2128 ik->initialize(CHECK);
2129
2130 ArchivableStaticFieldFinder finder(ik, field_name);
2131 ik->do_local_static_fields(&finder);
2132 if (!finder.found()) {
2133 stringStream st;
2134 st.print("Unable to find the static T_OBJECT field %s::%s", info->klass_name, info->field_name);
2135 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2136 }
2137
2138 info->klass = ik;
2139 info->offset = finder.offset();
2140 }
2141 }
2142
2143 void HeapShared::init_subgraph_entry_fields(TRAPS) {
2144 assert(CDSConfig::is_dumping_heap(), "must be");
2145 _dump_time_subgraph_info_table = new (mtClass)DumpTimeKlassSubGraphInfoTable();
2146 init_subgraph_entry_fields(archive_subgraph_entry_fields, CHECK);
2147 if (CDSConfig::is_dumping_full_module_graph()) {
2148 init_subgraph_entry_fields(fmg_archive_subgraph_entry_fields, CHECK);
2149 }
2150 }
2151
2152 #ifndef PRODUCT
2153 void HeapShared::setup_test_class(const char* test_class_name) {
2154 ArchivableStaticFieldInfo* p = archive_subgraph_entry_fields;
2155 int num_slots = sizeof(archive_subgraph_entry_fields) / sizeof(ArchivableStaticFieldInfo);
2156 assert(p[num_slots - 2].klass_name == nullptr, "must have empty slot that's patched below");
2157 assert(p[num_slots - 1].klass_name == nullptr, "must have empty slot that marks the end of the list");
2158
2159 if (test_class_name != nullptr) {
2160 p[num_slots - 2].klass_name = test_class_name;
2161 p[num_slots - 2].field_name = ARCHIVE_TEST_FIELD_NAME;
2162 }
2163 }
2164
2165 // See if ik is one of the test classes that are pulled in by -XX:ArchiveHeapTestClass
2166 // during runtime. This may be called before the module system is initialized so
2167 // we cannot rely on InstanceKlass::module(), etc.
2168 bool HeapShared::is_a_test_class_in_unnamed_module(Klass* ik) {
2169 if (_test_class != nullptr) {
2170 if (ik == _test_class) {
2171 return true;
2172 }
2173 Array<Klass*>* klasses = _test_class_record->subgraph_object_klasses();
2174 if (klasses == nullptr) {
2175 return false;
2176 }
2177
2178 for (int i = 0; i < klasses->length(); i++) {
2179 Klass* k = klasses->at(i);
2180 if (k == ik) {
2181 Symbol* name;
2182 if (k->is_instance_klass()) {
2183 name = InstanceKlass::cast(k)->name();
2184 } else if (k->is_objArray_klass()) {
2185 Klass* bk = ObjArrayKlass::cast(k)->bottom_klass();
2186 if (!bk->is_instance_klass()) {
2187 return false;
2188 }
2189 name = bk->name();
2190 } else {
2191 return false;
2192 }
2193
2194 // See KlassSubGraphInfo::check_allowed_klass() - we only allow test classes
2195 // to be:
2196 // (A) java.base classes (which must not be in the unnamed module)
2197 // (B) test classes which must be in the unnamed package of the unnamed module.
2198 // So if we see a '/' character in the class name, it must be in (A);
2199 // otherwise it must be in (B).
2200 if (name->index_of_at(0, "/", 1) >= 0) {
2201 return false; // (A)
2202 }
2203
2204 return true; // (B)
2205 }
2206 }
2207 }
2208
2209 return false;
2210 }
2211
2212 void HeapShared::initialize_test_class_from_archive(JavaThread* current) {
2213 Klass* k = _test_class;
2214 if (k != nullptr && ArchiveHeapLoader::is_in_use()) {
2215 JavaThread* THREAD = current;
2216 ExceptionMark em(THREAD);
2217 const ArchivedKlassSubGraphInfoRecord* record =
2218 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
2219
2220 // The _test_class is in the unnamed module, so it can't call CDS.initializeFromArchive()
2221 // from its <clinit> method. So we set up its "archivedObjects" field first, before
2222 // calling its <clinit>. This is not strictly clean, but it's a convenient way to write unit
2223 // test cases (see test/hotspot/jtreg/runtime/cds/appcds/cacheObject/ArchiveHeapTestClass.java).
2224 if (record != nullptr) {
2225 init_archived_fields_for(k, record);
2226 }
2227 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
2228 }
2229 }
2230 #endif
2231
2232 void HeapShared::init_for_dumping(TRAPS) {
2233 if (CDSConfig::is_dumping_heap()) {
2234 setup_test_class(ArchiveHeapTestClass);
2235 _dumped_interned_strings = new (mtClass)DumpedInternedStrings(INITIAL_TABLE_SIZE, MAX_TABLE_SIZE);
2236 init_subgraph_entry_fields(CHECK);
2237 }
2238 }
2239
2240 void HeapShared::archive_object_subgraphs(ArchivableStaticFieldInfo fields[],
2241 bool is_full_module_graph) {
2242 _num_total_subgraph_recordings = 0;
2243 _num_total_walked_objs = 0;
2244 _num_total_archived_objs = 0;
2245 _num_total_recorded_klasses = 0;
2246 _num_total_verifications = 0;
2247
2248 // For each class X that has one or more archived fields:
2249 // [1] Dump the subgraph of each archived field
2250 // [2] Create a list of all the class of the objects that can be reached
2251 // by any of these static fields.
2252 // At runtime, these classes are initialized before X's archived fields
2253 // are restored by HeapShared::initialize_from_archived_subgraph().
2254 for (int i = 0; fields[i].valid(); ) {
2255 ArchivableStaticFieldInfo* info = &fields[i];
2256 const char* klass_name = info->klass_name;
2257 start_recording_subgraph(info->klass, klass_name, is_full_module_graph);
2258
2259 ContextMark cm(klass_name);
2260 // If you have specified consecutive fields of the same klass in
2261 // fields[], these will be archived in the same
2262 // {start_recording_subgraph ... done_recording_subgraph} pass to
2263 // save time.
2264 for (; fields[i].valid(); i++) {
2265 ArchivableStaticFieldInfo* f = &fields[i];
2266 if (f->klass_name != klass_name) {
2267 break;
2268 }
2269
2270 ContextMark cm(f->field_name);
2271 archive_reachable_objects_from_static_field(f->klass, f->klass_name,
2272 f->offset, f->field_name);
2273 }
2274 done_recording_subgraph(info->klass, klass_name);
2275 }
2276
2277 log_info(cds, heap)("Archived subgraph records = %d",
2278 _num_total_subgraph_recordings);
2279 log_info(cds, heap)(" Walked %d objects", _num_total_walked_objs);
2280 log_info(cds, heap)(" Archived %d objects", _num_total_archived_objs);
2281 log_info(cds, heap)(" Recorded %d klasses", _num_total_recorded_klasses);
2282
2283 #ifndef PRODUCT
2284 for (int i = 0; fields[i].valid(); i++) {
2285 ArchivableStaticFieldInfo* f = &fields[i];
2286 verify_subgraph_from_static_field(f->klass, f->offset);
2287 }
2288 log_info(cds, heap)(" Verified %d references", _num_total_verifications);
2289 #endif
2290 }
2291
2292 // Not all the strings in the global StringTable are dumped into the archive, because
2293 // some of those strings may be only referenced by classes that are excluded from
2294 // the archive. We need to explicitly mark the strings that are:
2295 // [1] used by classes that WILL be archived;
2296 // [2] included in the SharedArchiveConfigFile.
2297 void HeapShared::add_to_dumped_interned_strings(oop string) {
2298 assert_at_safepoint(); // DumpedInternedStrings uses raw oops
2299 assert(!ArchiveHeapWriter::is_string_too_large_to_archive(string), "must be");
2300 bool created;
2301 _dumped_interned_strings->put_if_absent(string, true, &created);
2302 if (created) {
2303 // Prevent string deduplication from changing the value field to
2304 // something not in the archive.
2305 java_lang_String::set_deduplication_forbidden(string);
2306 _dumped_interned_strings->maybe_grow();
2307 }
2308 }
2309
2310 bool HeapShared::is_dumped_interned_string(oop o) {
2311 return _dumped_interned_strings->get(o) != nullptr;
2312 }
2313
2314 void HeapShared::debug_trace() {
2315 ResourceMark rm;
2316 oop referrer = _object_being_archived.referrer();
2317 if (referrer != nullptr) {
2318 LogStream ls(Log(cds, heap)::error());
2319 ls.print_cr("Reference trace");
2320 CDSHeapVerifier::trace_to_root(&ls, referrer);
2321 }
2322 }
2323
2324 #ifndef PRODUCT
2325 // At dump-time, find the location of all the non-null oop pointers in an archived heap
2326 // region. This way we can quickly relocate all the pointers without using
2327 // BasicOopIterateClosure at runtime.
2328 class FindEmbeddedNonNullPointers: public BasicOopIterateClosure {
2329 void* _start;
2330 BitMap *_oopmap;
2331 int _num_total_oops;
2332 int _num_null_oops;
2333 public:
2334 FindEmbeddedNonNullPointers(void* start, BitMap* oopmap)
2335 : _start(start), _oopmap(oopmap), _num_total_oops(0), _num_null_oops(0) {}
2336
2337 virtual void do_oop(narrowOop* p) {
2338 assert(UseCompressedOops, "sanity");
2339 _num_total_oops ++;
2340 narrowOop v = *p;
2341 if (!CompressedOops::is_null(v)) {
2342 size_t idx = p - (narrowOop*)_start;
2343 _oopmap->set_bit(idx);
2344 } else {
2345 _num_null_oops ++;
2346 }
2347 }
2348 virtual void do_oop(oop* p) {
2349 assert(!UseCompressedOops, "sanity");
2350 _num_total_oops ++;
2351 if ((*p) != nullptr) {
2352 size_t idx = p - (oop*)_start;
2353 _oopmap->set_bit(idx);
2354 } else {
2355 _num_null_oops ++;
2356 }
2357 }
2358 int num_total_oops() const { return _num_total_oops; }
2359 int num_null_oops() const { return _num_null_oops; }
2360 };
2361 #endif
2362
2363 void HeapShared::count_allocation(size_t size) {
2364 _total_obj_count ++;
2365 _total_obj_size += size;
2366 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
2367 if (size <= (size_t(1) << i)) {
2368 _alloc_count[i] ++;
2369 _alloc_size[i] += size;
2370 return;
2371 }
2372 }
2373 }
2374
2375 static double avg_size(size_t size, size_t count) {
2376 double avg = 0;
2377 if (count > 0) {
2378 avg = double(size * HeapWordSize) / double(count);
2379 }
2380 return avg;
2381 }
2382
2383 void HeapShared::print_stats() {
2384 size_t huge_count = _total_obj_count;
2385 size_t huge_size = _total_obj_size;
2386
2387 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
2388 size_t byte_size_limit = (size_t(1) << i) * HeapWordSize;
2389 size_t count = _alloc_count[i];
2390 size_t size = _alloc_size[i];
2391 log_info(cds, heap)("%8zu objects are <= %-6zu"
2392 " bytes (total %8zu bytes, avg %8.1f bytes)",
2393 count, byte_size_limit, size * HeapWordSize, avg_size(size, count));
2394 huge_count -= count;
2395 huge_size -= size;
2396 }
2397
2398 log_info(cds, heap)("%8zu huge objects (total %8zu bytes"
2399 ", avg %8.1f bytes)",
2400 huge_count, huge_size * HeapWordSize,
2401 avg_size(huge_size, huge_count));
2402 log_info(cds, heap)("%8zu total objects (total %8zu bytes"
2403 ", avg %8.1f bytes)",
2404 _total_obj_count, _total_obj_size * HeapWordSize,
2405 avg_size(_total_obj_size, _total_obj_count));
2406 }
2407
2408 bool HeapShared::is_archived_boot_layer_available(JavaThread* current) {
2409 TempNewSymbol klass_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_CLASS);
2410 InstanceKlass* k = SystemDictionary::find_instance_klass(current, klass_name, Handle());
2411 if (k == nullptr) {
2412 return false;
2413 } else {
2414 TempNewSymbol field_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_FIELD);
2415 TempNewSymbol field_signature = SymbolTable::new_symbol("Ljdk/internal/module/ArchivedBootLayer;");
2416 fieldDescriptor fd;
2417 if (k->find_field(field_name, field_signature, true, &fd) != nullptr) {
2418 oop m = k->java_mirror();
2419 oop f = m->obj_field(fd.offset());
2420 if (CompressedOops::is_null(f)) {
2421 return false;
2422 }
2423 } else {
2424 return false;
2425 }
2426 }
2427 return true;
2428 }
2429
2430 #endif // INCLUDE_CDS_JAVA_HEAP